Actions

Sonic the Hedgehog 2 (16-bit)/Hidden content

From Sonic Retro

Back to: Sonic the Hedgehog 2 (16-bit).

Level select

S2 level select.png

Play songs 19, 65, 09, 17 on the options screen, then hold A+Start on title screen.

Edit mode

Sonic2 MD DebugMode.png

From the level select menu, play songs 01, 09, 09, 02, 01, 01, 02, 04 (1992-11-24 - the worldwide launch date of Sonic 2). A Ring sound should trigger. Select a Zone and hold A until the title card disappears.

Edit mode does not work when playing as Tails in this game, even though the counters for debug mode are still intact here.

Night mode

Sonic2 MD NightMode.png

After enabling edit mode, select a level on the level select screen and hold C+Start until the title card disappears.

Get all Chaos Emeralds

From the level select menu, play songs 04, 01, 02, 06 on the sound test and a Chaos Emerald sound effect will trigger. This immediately gives the player all seven Chaos Emeralds, enabling Super Sonic.

Swap Tails for Miles

Sonic2 MD Comparison OptionsJP.png

Press Up Down Down Down Up at the title screen. This will cause all instances of "Tails" to change to "Miles", except in the Japanese version where the reverse will happen. This also toggles the trademark symbols on the Sega logo and the title screen.

14 continues

Sonic2 MD 14Continues.png

Play songs 01, 01, 02, 04 on the options screen. An incorrect sound command is issued, causing Oil Ocean Zone music to continue playing until a reset.

Unused content

Art

Tiles

Art Description
23


Sonic2 MD Map OOZ blocks.png
27


Sonic2 MD Map OOZ blocks.png
129


Sonic2 MD Map OOZ blocks.png
141


Sonic2 MD Map OOZ blocks.png
147


Sonic2 MD Map OOZ blocks.png
178


Sonic2 MD Map OOZ blocks.png
179


Sonic2 MD Map OOZ blocks.png
200


Sonic2 MD Map OOZ blocks.png
201


Sonic2 MD Map OOZ blocks.png
208


Sonic2 MD Map OOZ blocks.png
209


Sonic2 MD Map OOZ blocks.png
219


Sonic2 MD Map OOZ blocks.png
220


Sonic2 MD Map OOZ blocks.png
243


Sonic2 MD Map OOZ blocks.png
244


Sonic2 MD Map OOZ blocks.png
276


Sonic2 MD Map OOZ blocks.png
284


Sonic2 MD Map OOZ blocks.png
285


Sonic2 MD Map OOZ blocks.png
286


Sonic2 MD Map OOZ blocks.png
291


Sonic2 MD Map OOZ blocks.png
292


Sonic2 MD Map OOZ blocks.png
293


Sonic2 MD Map OOZ blocks.png
294


Sonic2 MD Map OOZ blocks.png
295


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296


Sonic2 MD Map OOZ blocks.png
297


Sonic2 MD Map OOZ blocks.png
298


Sonic2 MD Map OOZ blocks.png
299


Sonic2 MD Map OOZ blocks.png
300


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301


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302


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303


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304


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305


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308


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313


Sonic2 MD Map OOZ blocks.png
314


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319


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321


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324


Sonic2 MD Map OOZ blocks.png
326


Sonic2 MD Map OOZ blocks.png
327


Sonic2 MD Map OOZ blocks.png
343


Sonic2 MD Map OOZ blocks.png
347


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386


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387


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388


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391


Sonic2 MD Map OOZ blocks.png
393


Sonic2 MD Map OOZ blocks.png
394


Sonic2 MD Map OOZ blocks.png
398


Sonic2 MD Map OOZ blocks.png
427


Sonic2 MD Map OOZ blocks.png
527


Sonic2 MD Map OOZ blocks.png
528


Sonic2 MD Map OOZ blocks.png
534


Sonic2 MD Map OOZ blocks.png
535


Sonic2 MD Map OOZ blocks.png
536


Sonic2 MD Map OOZ blocks.png
592


Sonic2 MD Map OOZ blocks.png
606


Sonic2 MD Map OOZ blocks.png
610


Sonic2 MD Map OOZ blocks.png
611


Sonic2 MD Map OOZ blocks.png
624


Sonic2 MD Map OOZ blocks.png
626


Sonic2 MD Map OOZ blocks.png
638


Sonic2 MD Map OOZ blocks.png
650


Sonic2 MD Map OOZ blocks.png
651


Sonic2 MD Map OOZ blocks.png
659


Sonic2 MD Map OOZ blocks.png
The old ball launcher among other graphics in Oil Ocean Zone.

Tile IDs: 017, 01B, 081, 08D, 093, 0B2, 0B3, 0C8, 0C9, 0D0, 0D1, 0DB, 0DC, 0F3, 0F4, 114, 11C, 11D, 11E, 123, 124, 125, 126, 127, 128, 129, 12A, 12B, 12C, 12D, 12E, 12F, 130, 131, 134, 139, 13A, 13F, 141, 144, 146, 147, 157, 15B, 182, 183, 184, 187, 189, 18A, 18E, 1AB, 20F, 210, 216, 217, 218, 250, 25E, 262, 263, 270, 272, 27E, 28A, 28B, 293.

35


Sonic2 MD Map MZ blocks.png
36


Sonic2 MD Map MZ blocks.png
37


Sonic2 MD Map MZ blocks.png
38


Sonic2 MD Map MZ blocks.png
40


Sonic2 MD Map MZ blocks.png
41


Sonic2 MD Map MZ blocks.png
72


Sonic2 MD Map MZ blocks.png
73


Sonic2 MD Map MZ blocks.png
74


Sonic2 MD Map MZ blocks.png
75


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76


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77


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78


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79


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80


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81


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82


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83


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84


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85


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86


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87


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88


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89


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90


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91


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92


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93


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94


Sonic2 MD Map MZ blocks.png
95


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96


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97


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98


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100


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101


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102


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103


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104


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159


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194


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308


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309


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310


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311


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312


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313


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314


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315


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316


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317


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318


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319


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320


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321


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322


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323


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324


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325


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327


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372


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379


Sonic2 MD Map MZ blocks.png
406


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407


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408


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409


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410


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411


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412


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413


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414


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417


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418


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431


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432


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433


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434


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435


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436


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437


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438


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439


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440


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441


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442


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443


Sonic2 MD Map MZ blocks.png
444


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445


Sonic2 MD Map MZ blocks.png
446


Sonic2 MD Map MZ blocks.png
447


Sonic2 MD Map MZ blocks.png
448


Sonic2 MD Map MZ blocks.png
449


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450


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451


Sonic2 MD Map MZ blocks.png
452


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453


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484


Sonic2 MD Map MZ blocks.png
486


Sonic2 MD Map MZ blocks.png
487


Sonic2 MD Map MZ blocks.png
488


Sonic2 MD Map MZ blocks.png
Remnants of the diagonal platforms and some unused grey pipes in Metropolis Zone.

Tile IDs: 023, 024, 025, 026, 028, 029, 048, 049, 04A, 04B, 04C, 04D, 04E, 04F, 050, 051, 052, 053, 054, 055, 056, 057, 058, 059, 05A, 05B, 05C, 05D, 05E, 05F, 060, 061, 062, 064, 065, 066, 067, 068, 09F, 0C2, 134, 135, 136, 137, 138, 139, 13A, 13B, 13C, 13D, 13E, 13F, 140, 141, 142, 143, 144, 145, 147, 174, 17B, 196, 197, 198, 199, 19A, 19B, 19C, 19D, 19E, 1A1, 1A2, 1AF, 1B0, 1B1, 1B2, 1B3, 1B4, 1B5, 1B6, 1B7, 1B8, 1B9, 1BA, 1BB, 1BC, 1BD, 1BE, 1BF, 1C0, 1C1, 1C2, 1C3, 1C4, 1C5, 1E4, 1E6, 1E7, 1E8.

601


Sonic2 MD Map SCZ blocks.png
610


Sonic2 MD Map SCZ blocks.png
616


Sonic2 MD Map SCZ blocks.png
636


Sonic2 MD Map SCZ blocks.png
Some unused clouds in Sky Chase Zone.

Tile IDs: 259, 262, 268, 27C

327


Sonic2 MD Map WFZ blocks.png
333


Sonic2 MD Map WFZ blocks.png
337


Sonic2 MD Map WFZ blocks.png
343


Sonic2 MD Map WFZ blocks.png
354


Sonic2 MD Map WFZ blocks.png
364


Sonic2 MD Map WFZ blocks.png
443


Sonic2 MD Map WFZ blocks.png
504


Sonic2 MD Map WFZ blocks.png
510


Sonic2 MD Map WFZ blocks.png
511


Sonic2 MD Map WFZ blocks.png
513


Sonic2 MD Map WFZ blocks.png
528


Sonic2 MD Map WFZ blocks.png
529


Sonic2 MD Map WFZ blocks.png
533


Sonic2 MD Map WFZ blocks.png
537


Sonic2 MD Map WFZ blocks.png
538


Sonic2 MD Map WFZ blocks.png
551


Sonic2 MD Map WFZ blocks.png
552


Sonic2 MD Map WFZ blocks.png
672


Sonic2 MD Map WFZ blocks.png
674


Sonic2 MD Map WFZ blocks.png
695


Sonic2 MD Map WFZ blocks.png
739


Sonic2 MD Map WFZ blocks.png
Wing Fortress Zone tiles, possibly also desgined for Sky Chase Zone.

Tile IDs: 147, 14D, 151, 157, 162, 16C, 1BB, 1F8, 1FE, 1FF, 201, 210, 211, 215, 219, 21A, 227, 228, 2A0, 2A2, 2B7, 2E3.

Sprites

Art Description
An animation very similar to one used in Wing Fortress Zone when Sonic grabs the panels on the side of the ship. However, this is vertical. Its frame IDs are 52 and 53.
An alternate death frame for Sonic, defined in animation 16 with a frame ID of 5E. This returns from (and is also unused in) Sonic the Hedgehog.
Sonic2 MD Sprite CPZSirenLights.gif
Unused decorative objects for Chemical Plant Zone, stored at 0x0383-0x0393 in VRAM. These can be placed in the iOS/Android 2013 version's debug mode.
Spr cpzboss.gif
An animation for Water Eggman which shows Dr. Eggman dropping chemicals on himself. This animation has been around since the Nick Arcade prototype, but it was never implemented. A fix to implement the lost animation can be found here.
Sonic2 MD Sprite OOZSpringHolder.png
A holder for Oil Ocean Zone's ball and spring object (see below). This appeared in the Simon Wai prototype, and is still loaded into VRAM in the final game.
An unused animation for Aquis spitting up oil, along with an oil spray.
Balkiry2.png
Unused frame of the Balkiry badnik with landing gear. It's possible that they were originally intended to take off from the Wing Fortress Zone as it passed by. If a Balkiry is selected in debug mode, this sprite will be seen instead of its flying one.
S2-Turtle.gif
Walking sprites of Tocky, who pops out of the Badniks in Sky Chase Zone. Normally the player will never see this, since the animal never has the opportunity to hit the ground. In order to see it, the player must use debug mode to create and destroy a Badnik while the Wing Fortress passes by. This animation would later make an appearance in Sonic Mania, as Tocky can be found in Titanic Monarch Zone.
S2-Picky.gif
Picky, a returning animal from the original Sonic the Hedgehog, is present in Death Egg Zone. However, there are no Badniks or animal capsules, so he's never seen.
Sonic2-RobotnikLaugh.gif
In Death Egg Zone, getting hit with one or more Rings during the Mecha Sonic battle causes Eggman to laugh. However, this is never actually seen outside of debug mode because the Zone has no Rings. In the 2013 mobile remake, this animation can be seen normally if the player dies during the fight. In 3D Sonic the Hedgehog 2 it can also be seen if the player is hurt by Mecha Sonic if the Ring Keeper mode is on.
HPZiconS2.png
Level Select icon for Hidden Palace Zone, which never made it into the final game. The art however, is present in Sonic 3's level select. Pro Action Replay code 0096D8:0303 will cause it to replace the Emerald Hill Zone icon in the Stage Select.

Objects

Placeable in edit mode

Art Description
Aquatic ruin door.png
Unused door barriers for Aquatic Ruin Zone, which function like the door barriers found in other Zones.
Sonic2-mrzobject.png
A strange platform made of Rings in Mystic Cave Zone. When placed, this object will slowly swing in an anti-clockwise direction and can be stood on. This object has existed since the Simon Wai prototype, and its object ID is $73.
Sonic2PreBeta MD Sprite OOZ Ball.png
S2button.png
A ball and spring object, which can be placed in Oil Ocean Zone. If a button is placed near it and pressed, the ball will pop out and start rolling in whichever direction Sonic was facing when the object was placed. It does not collide with objects (such as breakable floors or elevators), and it will go up slopes and even vertical walls without slowing or stopping. It is used in the Simon Wai and alpha prototypes. Its object ID is $46.
Sonic2Alpha MD Sprite OOZTube.png
A horizontal version of the breakable pressure stopper in Oil Ocean Zone. These can be jumped on, but they will send Sonic and Tails left or right rather than up. Once Sonic is travelling, the player can't make him stop unless he collides with an object - even in edit mode the player will continue to travel. This would have been used in the Simon Wai layout of the Zone, but has no purpose in the final layout.
Sonic2-giantlaser.gif
Large laser shooting through a spinning platform in Wing Fortress Zone. If the sub-ID of the spinning platforms has bit 02 of their subtype set but not 04, they will become this object. Its object ID is $B7.
Sonic2-wfz-spinnything2.gif
Weird spinning pole in Wing Fortress Zone that acts like a Badnik - the player can destroy it, and it can hurt them, but it doesn't actually move. Its object ID is $BF.

Others

Art Description
Sonic2 MD Sprite Monitors.png
A static or blank monitor which harms the player when broken. Never seen in-game. To see it, a monitor's subtype should be set to 00.
A hovering platform for Chemical Plant Zone that has been around since the Nick Arcade prototype. Every 1024 frames, it will slowly rise up for 128 frames, float in the air, then come back down 128 frames later. The amount of time it floats in the air is 128*(lower four bits of subtype) frames. The upper four bits can be used to offset when it starts to rise in the air. Its object ID is $0C.
The blue bubble snakes in Chemical Plant Zone have many subtypes that define their movement pattern (00-0F for jumping back and forth, 10-1F for jumping between the floor and ceiling) and their length, which can be any number of segments between 1 and 16. However, only those that are 6 segments long are used (subtypes 05 and 15), leaving all other subtypes unused.
Although very similar to the small platforms used in Metropolis Zone, this platform behaves strangely, usually rising at an angle. Its object ID is $6C.
The emerald-shaped object that was used in Hidden Palace Zone to block off a tube. The graphics are long gone, but the code is still there. It's a simple solid indestructible object and its coding hasn't changed since the Nick Arcade prototype. Its object ID is $12.
The waterfall object from Hidden Palace Zone, which is also left over. Again, the graphics no longer exist in the ROM. Its height is equal to 16*(lower five bits of subtype)+16 pixels. Placing one with a subtype greater than 17 will spawn garbage objects on the right. Its object ID is $13.
The spinning log spikes from Sonic the Hedgehog's Green Hill Zone. Unfortunately, the graphics have been deleted, but the coding is intact. Its object ID is $17.

Score tally

Sonic2UnusedScoreTally.png

This configuration of the score tally is unused but was meant for Zones with a single Act (Sky Chase Zone, etc). It can be made to appear by using debug mode and placing, then breaking a capsule.

Level chunks

Emerald Hill Zone

[[File:
1


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|120x120px|]]
01
[[File:
5


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05
[[File:
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0E
[[File:
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15
[[File:
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17
[[File:
50


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32
[[File:
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56
[[File:
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7A
[[File:
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7F
[[File:
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A6
[[File:
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AE
[[File:
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D2
[[File:
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D8
[[File:
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D9
[[File:
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DA
[[File:
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DC
[[File:
231


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E7
[[File:
237


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ED


Chemical Plant Zone

[[File:
29


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1D
[[File:
74


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4A
[[File:
137


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89

Casino Night Zone

[[File:
34


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22
[[File:
48


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30
[[File:
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44
[[File:
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48
[[File:
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49
[[File:
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50
[[File:
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53
[[File:
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54
[[File:
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57
[[File:
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5A
[[File:
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6D
[[File:
111


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6F
[[File:
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70
[[File:
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72
[[File:
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77
[[File:
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7C
[[File:
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EA

Hill Top Zone

[[File:
166


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A6
[[File:
174


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AE
[[File:
210


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D2
[[File:
216


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D8
[[File:
217


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D9
[[File:
218


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DA
[[File:
220


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DC
[[File:
231


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E7
[[File:
237


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ED
[[File:
245


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F5

Mystic Cave Zone

[[File:
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1E
[[File:
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3A
[[File:
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4F
[[File:
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88
[[File:
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CA
[[File:
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CD
[[File:
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CE
[[File:
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CF
[[File:
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D0
[[File:
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D1
[[File:
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D7
[[File:
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E6

Oil Ocean Zone

None of the chunks listed here are referenced in the table that the game checks to determine whether or not Sonic & Tails should slide.

[[File:
9


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|120x120px|]]
09
[[File:
43


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2B
[[File:
44


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2C
[[File:
89


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59
[[File:
94


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5E
[[File:
98


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62
[[File:
109


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6D
[[File:
115


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73
[[File:
118


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76
[[File:
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79
[[File:
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81
[[File:
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84
[[File:
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86
[[File:
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8A
[[File:
148


Sonic2 MD Map OOZ chunks.png
|120x120px|]]
94
[[File:
151


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|120x120px|]]
97
[[File:
158


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|120x120px|]]
9E
[[File:
160


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|120x120px|]]
A0
[[File:
165


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|120x120px|]]
A5
[[File:
166


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|120x120px|]]
A6
[[File:
169


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|120x120px|]]
A9
[[File:
170


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|120x120px|]]
AA
[[File:
178


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|120x120px|]]
B2
[[File:
188


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|120x120px|]]
BC
[[File:
204


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|120x120px|]]
CC
[[File:
208


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|120x120px|]]
D0
[[File:
210


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|120x120px|]]
D2
[[File:
211


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|120x120px|]]
D3
[[File:
214


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|120x120px|]]
D6
[[File:
219


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|120x120px|]]
DB
[[File:
220


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|120x120px|]]
DC
[[File:
222


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|120x120px|]]
DE
[[File:
224


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|120x120px|]]
E0
[[File:
233


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|120x120px|]]
E9
[[File:
234


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|120x120px|]]
EA
[[File:
240


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|120x120px|]]
F0
[[File:
245


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|120x120px|]]
F5
[[File:
246


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|120x120px|]]
F6
[[File:
248


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|120x120px|]]
F8
[[File:
249


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|120x120px|]]
F9
[[File:
255


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|120x120px|]]
FF

Metropolis Zone

[[File:
3


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|120x120px|]]
03
[[File:
105


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|120x120px|]]
69
[[File:
121


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|120x120px|]]
79
[[File:
125


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|120x120px|]]
7D
[[File:
138


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|120x120px|]]
8A
[[File:
182


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|120x120px|]]
B6
[[File:
208


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|120x120px|]]
D0
[[File:
213


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|120x120px|]]
D5
[[File:
220


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|120x120px|]]
DC

Wing Fortress Zone

[[File:
67


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|120x120px|]]
43
[[File:
72


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|120x120px|]]
48
[[File:
79


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|120x120px|]]
4F
[[File:
87


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|120x120px|]]
57
[[File:
98


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|120x120px|]]
62
[[File:
152


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|120x120px|]]
98
[[File:
221


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|120x120px|]]
DD

Background data

Aquatic Ruin Zone

Code exists to scroll part of the top tree background layer at a different rate, giving the impression it is closer to the camera. As the code executes, the effect is reverted, so cannot be not seen without hacking. It is theorised that this may be a leftover from an early version of the level, as with the final art the seam is quite obvious.

Hill Top Zone

Hill Top Zone's background is partially optimised for 2-player mode; the background scrolls independently for both players, which cannot be said for other 1-player only levels. However, the parallax effect for the clouds is missing and some parts are corrupted, and while sharing data with Emerald Hill Zone means the foreground also renders correctly, objects are not optimised, meaning the experience is still noticeably buggy.

The final version of Hill Top Zone is also not suited to 2-player thanks to some level gimmicks, such as its inside lava sections; these make it impossible to back-track to the beginning of the stage by creating dead-ends, so if the two players were at opposite ends, the slower player would in theory get stuck.

Oil Ocean Zone

Due to the way scrolling is handled in Oil Ocean Zone, part of the background is never seen.

Audio

Music

Audio Description
In the sound test, song $10 is a unused song. This has been established to be the music meant for Hidden Palace Zone.

Sound effects

Sounds not used anywhere in the game can be heard in the sound test, some of which are leftovers from the original Sonic the Hedgehog.

Audio ID Description
Sonic the Hedgehog leftovers
29 The sound for touching the R, Up, and Down Special Stage blocks.
31 Scrap Brain Zone electricity.
3A The sound for touching the colour-changing diamonds in the Special Stage.
43 The sound for entering Giant Rings at the end of an Act.
47 The chain pulling sound from Marble Zone.
49 The bonus point tags found at the end of an Act.
Other sounds
38 Sounds similar to the sound of spikes popping up. Also unused in Sonic 1.
51 Unknown. Sounds like something popping or skidding on the ground.
52 A low siren, similar to $53 which is used in the 2-Player mode.
68 Sounds like a slightly shorter version of Mystic Cave Zone's bridges stopping in place ($69).

Level slots

Like its predecessor, Sonic 2 on the Mega Drive lays out its levels in a different order internally to how the player sees them when playing through the game. It gives some clues as to what the original progression looked like, and the differences are quite significant.

The internal level order can be seen by using Pro Action Replay code (FFFE10:??00), substituting the question marks with the hexadecimal values for the level slots described in the table below and then attempting to enter any level (any number past 10 crashes the game). Metropolis Zone covers two level slots as it has three Acts.

Level slot Level name In-game order Comments
00 Emerald Hill Zone 01
01 Unknown Plays Emerald Hill Zone's music.
02 Wood Zone Scrapped Palette is all that remains. Plays Metropolis Zone's music.
03 Unknown Plays Oil Ocean Zone's music.
04 Metropolis Zone 08
05 Metropolis Zone (Act 3) 09
06 Wing Fortress Zone 11
07 Hill Top Zone 05
08 Hidden Palace Zone Scrapped Palette and object/ring locations remain. Plays unused track #10.
09 Unknown Plays Sky Chase Zone's music.
100A Oil Ocean Zone 07
110B Mystic Cave Zone 06
120C Casino Night Zone 04
130D Chemical Plant Zone 02
140E Death Egg Zone 12 Occupied by Genocide City Zone in prototypes.
150F Aquatic Ruin Zone 03
1610 Sky Chase Zone 10

This order is mirrored (with empty slots cut out) by some prototype level select screens. All empty slots are fundamentally broken, loading varying amounts of graphics data from Emerald Hill Zone (depending on the build).

Three slots in the game remain empty in all versions of Sonic 2 (save for the very early Nick Arcade prototype which is using the Sonic 1 level order). There has been much speculation over the years about what these slots were reserved for (if anything) - possible candidates include Brenda Ross's "desert" and "winter" zones which were thought to be at least partially complete, or possibly Genocide City Zone before it was transformed into Metropolis Zone Act 3. The team are known to have explored many level ideas during development, most of which did not make it past the design stage.

Commentary found in the Sonic Jam strategy guide reveals that the level order could have been even more different. It states that Chemical Plant Zone was meant to be the 10th Zone back when the game was planned as an 18-Zone game.

Unused slots

In all cases, Acts 1 and 2 are identical. Metropolis "Act 4" loads a duplicate of Metropolis Act 3 (with a different starting position) while "Act 2" of Sky Chase, Wing Fortress and Death Egg load their Act 1 counterparts without objects.

Inaccessible Rings

There are some levels that have Rings in places that can't be reached normally. This makes getting a Perfect Bonus in these stages impossible.[1]

Screenshot Level Approximate coordinates Description
Sonic2AquaticRuinZone-Rings.png
Aquatic Ruin Zone Act 2 1FA90626 Two horizontally lined rings.
Sonic2CasinoNightZone-Rings.png
Casino Night Zone Act 2 027F00F8 Two groups of seven rings. These are right at the start of the level but cannot be reached with a jump or using nearby objects.
Sonic2MysticCaveZone-Rings1.png
Sonic2MysticCaveZone-Rings2.png
Mystic Cave Zone Act 2 16050156
1712016D
Three horizontally lined rings, and a nearby curve of rings, similar to ones found near swings. Both sets of rings are found in the ceiling.
Sonic2OilOceanZone-Rings1.png
Sonic2OilOceanZone-Rings2.png
Sonic2OilOceanZone-Rings3.png
Oil Ocean Zone Act 2 1A0001F8
0B9F03B0
1245021C
Three horizontally lined rings, close to the launcher and invincibility monitor. Three vertically lined rings stuck in a block which prohibits access to them. Rings in a upside down v shape pattern. They are stuck inside the wall, thus unaccessable.
Sonic2MetropolisZone-Rings.png
Metropolis Zone Act 2 02C0043F Three slanted rings, in the floor that has a ten-ring monitor and a cog close-by.

Cheat device codes

These are cheat codes that can only be used with game enhancer devices. Support for these codes is available in most emulators. There are two versions of this game. If one code doesn't work on your game, then try the other.

Game Genie

Official codes (REV00)

Code Effect Reference
SATA-DJTJ Rings worth 2 (player 1).
SATA-DNTJ Rings worth 3 (player 1).
SATA-DTTJ Rings worth 4 (player 1).
SATA-DYTJ Rings worth 5 (player 1).
SATA-D2TJ Rings worth 6 (player 1).
SATA-D6TJ Rings worth 7 (player 1).
SATA-DATJ Rings worth 8 (player 1).
AE8A-AADN Start with 1 life instead of 3 (player 1).
AY8A-AADN Start with 5 lives (player 1).
A68A-AADN Start with 7 lives (player 1).
BE8A-AADN Start with 9 lives (player 1).
DE8A-AADN Start with 25 lives (player 1).
GJ8A-AADN Start with 50 lives (player 1).
KN8A-AADN Start with 75 lives (player 1).
NN8A-AADN Start with 99 lives (player 1).
JW3A-CA4Y Infinite lives (player 1).
SATA-DJW8 Rings worth 2 (player 2).
SATA-DNW8 Rings worth 3 (player 2).
SATA-DTW8 Rings worth 4 (player 2).
SATA-DYW8 Rings worth 5 (player 2).
SATA-D2W8 Rings worth 6 (player 2).
SATA-D6W8 Rings worth 7 (player 2).
SATA-DAW8 Rings worth 8 (player 2).
AE8A-AADW Start with 1 life instead of 3 (player 2).
AY8A-AADW Start with 5 lives (player 2).
A68A-AADW Start with 7 lives (player 2).
BE8A-AADW Start with 9 lives (player 2).
DE8A-AADW Start with 25 lives (player 2).
GJ8A-AADW Start with 50 lives (player 2).
KN8A-AADW Start with 75 lives (player 2).
NN8A-AADW Start with 99 lives (player 2).
JXGA-CA7W Infinite lives (player 2).
KBVT-CAE2 Jump lower.
FVVT-CAE2 Jump a little higher.
EBVT-CAE2 Jump a lot higher (Switch off if you get stuck somewhere or want to go in the water).
CBVT-CAE2 Jump really high (Switch off if you get stuck somewhere or want to go in the water).
A02T-CAGL Sonic stays invincible for a shorter time after getting hit.
982T-CAGL Sonic stays invincible for a longer time after getting hit.
ALTA-CA82 Sonic becomes invisible and invincible for the rest of the level after getting hit.
ALTA-CA9Y Once invincible [stars], Sonic stays Invincible for the rest of the level.
ATTT-CA58 Sonic doesn't lose rings when hit.
ATTT-CA6W Tails doesn't lose rings when hit.
ATTT-CA6W Only 1 ring needed instead of 50 to enter special stage.
SBJA-HJV2 Rings worth 2 in special stages (Sonic only/Doesn't show on screen).
SBJA-HNV2 Rings worth 3 in special stages (Sonic only/Doesn't show on screen).
SBJA-HTV2 Rings worth 4 in special stages (Sonic only/Doesn't show on screen).
SBJA-HYV2 Rings worth 5 in special stages (Sonic only/Doesn't show on screen).
SBJA-H2V2 Rings worth 6 in special stages (Sonic only/Doesn't show on screen).
SBJA-H6V2 Rings worth 7 in special stages (Sonic only/Doesn't show on screen).
SBJA-HAV2 Rings worth 8 in special stages (Sonic only/Doesn't show on screen).
SBJA-HJV8 Rings worth 2 in special stage (Tails only/Doesn't show on screen).
SBJA-HNV8 Rings worth 3 in special stages (Tails only/Doesn't show on screen).
SBJA-HTV8 Rings worth 4 in special stages (Tails only/Doesn't show on screen).
SBJA-HYV8 Rings worth 5 in special stages (Tails only/Doesn't show on screen).
SBJA-H2V8 Rings worth 6 in special stages (Tails only/Doesn't show on screen).
SBJA-H6V8 Rings worth 7 in special stages (Tails only/Doesn't show on screen).
SBJA-HAV8 Rings worth 8 in special stages (Tails only/Doesn't show on screen).
ACZT-CACN Need 0 chaos emeralds to become Super Sonic (Don't grab more than needed).
AGZT-CACN Need 1 Chaos Emerald to become Super Sonic (Don't grab more than needed).
ALZT-CACN Need 2 chaos emeralds to become Super Sonic (Don't grab more than needed).
ARZT-CACN Need 3 chaos emeralds to become Super Sonic (Don't grab more than needed).
AWZT-CACN Need 4 chaos emeralds to become Super Sonic (Don't grab more than needed).
A0ZT-CACN Need 5 chaos emeralds to become Super Sonic (Don't grab more than needed).
A4ZT-CACN Need 6 chaos emeralds to become Super Sonic (Don't grab more than needed).
AGZT-CACY + K4ZT-CA92 Need 1 ring to become Super Sonic, don't lose rings with time.
A0ZT-CACY Need 5 rings to become Super Sonic.
BLZT-CACY Need 10 rings to become Super Sonic.
DGZT-CACY Need 25 rings to become Super Sonic.
FCZT-CACY Need 40 rings to become Super Sonic.
K4ZT-CA92 Super Sonic doesn't lose rings with time.
RE8A-A60G Level select menu enabled.
2VAT-BCRA Start most levels with some rings (1 player game only).

Official codes (REV01)

Code Effect Reference
SAST-DJ1A Rings worth 2 (player 1).
SAST-DN1A Rings worth 3 (player 1).
SAST-DT1A Rings worth 4 (player 1).
SAST-DY1A Rings worth 5 (player 1).
SAST-D21A Rings worth 6 (player 1).
SAST-D61A Rings worth 7 (player 1).
SAST-DA1A Rings worth 8 (player 1).
AE8A-AAD2 Start with 1 life instead of 3 (player 1).
AY8A-AAD2 Start with 5 lives (player 1).
A68A-AAD2 Start with 7 lives (player 1).
BE8A-AAD2 Start with 9 lives (player 1).
DE8A-AAD2 Start with 25 lives (player 1).
GJ8A-AAD2 Start with 50 lives (player 1).
KN8A-AAD2 Start with 75 lives (player 1).
NN8A-AAD2 Start with 99 lives (player 1).
JW3A-CA4J Infinite lives (player 1).
SATA-DJVW Rings worth 2 (player 2).
SATA-DNVW Rings worth 3 (player 2).
SATA-DTVW Rings worth 4 (player 2).
SATA-DYVW Rings worth 5 (player 2).
SATA-D2VW Rings worth 6 (player 2).
SATA-D6VW Rings worth 7 (player 2).
SATA-DAVW Rings worth 8 (player 2).
AE8A-AAD8 Start with 1 life instead of 3 (player 2).
AY8A-AAD8 Start with 5 lives (player 2).
A68A-AAD8 Start with 7 lives (player 2).
BE8A-AAD8 Start with 9 lives (player 2).
DE8A-AAD8 Start with 25 lives (player 2).
GJ8A-AAD8 Start with 50 lives (player 2).
KN8A-AAD8 Start with 75 lives (player 2).
NN8A-AAD8 Start with 99 lives (player 2).
JXGA-CA7G Infinite lives (player 2).
KBVT-CAE2 Jump lower.
FVVT-CAE2 Jump a little higher.
EBVT-CAE2 Jump a lot higher (Switch off if you get stuck somewhere or want to go in the water).
CBVT-CAE2 Jump really high (Switch off if you get stuck somewhere or want to go in the water).
A02T-CAF8 Sonic stays invincible for a shorter time after getting hit.
982T-CAF8 Sonic stays invincible for a longer time after getting hit.
ALTA-CA8N Sonic becomes invisible and invincible for the rest of the level after getting hit.
ALTA-CA9J Once invincible [stars], Sonic stays Invincible for the rest of the level.
ATTT-CA4W Sonic doesn't lose rings when hit.
ATTT-CA5G Tails doesn't lose rings when hit.
AH2T-CAH6 Only 1 ring needed instead of 50 to enter special stage.
SBJA-HJWJ Rings worth 2 in special stages (Sonic only/Doesn't show on screen).
SBJA-HNWJ Rings worth 3 in special stages (Sonic only/Doesn't show on screen).
SBJA-HTWJ Rings worth 4 in special stages (Sonic only/Doesn't show on screen).
SBJA-HYWJ Rings worth 5 in special stages (Sonic only/Doesn't show on screen).
SBJA-H2WJ Rings worth 6 in special stages (Sonic only/Doesn't show on screen).
SBJA-H6WJ Rings worth 7 in special stages (Sonic only/Doesn't show on screen).
SBJA-HAWJ Rings worth 8 in special stages (Sonic only/Doesn't show on screen).
SBJA-HJWR Rings worth 2 in special stage (Tails only/Doesn't show on screen).
SBJA-HNWR Rings worth 3 in special stages (Tails only/Doesn't show on screen).
SBJA-HTWR Rings worth 4 in special stages (Tails only/Doesn't show on screen).
SBJA-HYWR Rings worth 5 in special stages (Tails only/Doesn't show on screen).
SBJA-H2WR Rings worth 6 in special stages (Tails only/Doesn't show on screen).
SBJA-H6WR Rings worth 7 in special stages (Tails only/Doesn't show on screen).
SBJA-HAWR Rings worth 8 in special stages (Tails only/Doesn't show on screen).
ACZT-CACA Need 0 chaos emeralds to become Super Sonic (Don't grab more than needed).
AGZT-CACA Need 1 Chaos Emerald to become Super Sonic (Don't grab more than needed).
ALZT-CACA Need 2 chaos emeralds to become Super Sonic (Don't grab more than needed).
ARZT-CACA Need 3 chaos emeralds to become Super Sonic (Don't grab more than needed).
AWZT-CACA Need 4 chaos emeralds to become Super Sonic (Don't grab more than needed).
A0ZT-CACA Need 5 chaos emeralds to become Super Sonic (Don't grab more than needed).
A4ZT-CACA Need 6 chaos emeralds to become Super Sonic (Don't grab more than needed).
AGZT-CACJ + K4ZT-CA9N Need 1 ring to become Super Sonic, don't lose rings with time.
A0ZT-CACJ Need 5 rings to become Super Sonic.
BLZT-CACJ Need 10 rings to become Super Sonic.
DGZT-CACJ Need 25 rings to become Super Sonic.
FCZT-CACJ Need 40 rings to become Super Sonic.
K4ZT-CA9N Super Sonic doesn't lose rings with time.
RE8A-A60W Level select menu enabled.
2VAT-BCRN Start most levels with some rings (1 player game only).
GJ8A-AA4G Skip straight to the ending sequence.

Unofficial codes (REV00)

Code Effect
ADFT-8AF6 Regular level music plays when turning into Super Sonic.
ACLA-ATDR Access Hidden Palace Zone by selecting Death Egg on the Level Select menu (no solid floors, glitched graphics, etc).

Unofficial codes (REV01)

Code Effect
ACZT-CACA Become Super Sonic With 0 Emeralds.
ADFT-8AF6 Regular level music plays when turning into Super Sonic.
982T-C9F8 Keep flashing after hit/Invincible (If you have rings).
ACLA-ATD4 Access Hidden Palace Zone by selecting Death Egg on the Level Select menu (no solid floors, glitched graphics, etc).
ACLA-AECY Access Wood Zone by selecting Emerald Hill Zone on the Stage Select screen. (Buggy, pallete-swapped Emerald Hill Zone).

Action Replay

Due to the fact that Pro Action Replay Effects RAM and that RAM is the same regardless of the game revision there is no need for version specific codes. These codes should work in all versions.

Unofficial codes

Code Effect
FFFE12:0009 Infinite Lives.
FFFE20:00C8 Infinite Rings.
FFB030:00FF Invincibility For Sonic (Enemies Can't Touch You/Can't collect Rings).
FFB06A:01 Invincibility For Tails (Always Have Shield).
FFB070:00FF Invincibility For Tails (Enemies Can't Touch You).
FFB028:FA Infinite Time Underwater For Sonic.
FFB068:FA Infinite Time Underwater For Tails.
FFF761:6410 Sonic has Super Speed.
FFFEC1:6410 Tails has Super Speed.
FFFFB1:07 Enable Super Sonic (All Chaos Emeralds Collected).
FFB02B:01 Always have Shield.
FFFE19:01 Play As Super Sonic (No Powers).
FFF711:?? HUD Display Modifier (00: Off, 01: On).
FFFFFA:0100 Enable Debug Mode.
FFFFD0:0100 Enable Stage Select (A+Start on Title Screen).
FFFE10:XXYY Stage/Act Modifier (XX: Zone, YY: Level).
  • 00 - Emerald Hill
  • 04 - Metropolis
  • 05 - Metropolis 3
  • 06 - Wing Fortress
  • 07 - Hill Top
  • 08 - Hidden Palace (!)
  • 0A - Oil Ocean
  • 0B - Mystic Cave
  • 0C - Casino Night
  • 0D - Chemical Plant
  • 0E - Death Egg
  • 0F - Aquatic Ruin
  • 10 - Sky Chase
FFB461:01 Defeat Final Stage Bosses With 1 Hit.
FFB521:01 Defeat Stage 1 Robotnik With 1 Hit.
FFB621:01 Defeat Stage 2 Robotnik With 1 Hit.
FFB721:01 Defeat Stage 3 Robotnik With 1 Hit.
FFB821:01 Defeat Stage 4 Robotnik With 1 Hit.
FFB921:01 Defeat Stage 5 Robotnik With 1 Hit.
FFBA21:01 Defeat Stage 6 Robotnik With 1 Hit.
FFBB21:01 Defeat Stage 7 Robotnik With 1 Hit.
FFBC21:01 Defeat Stage 8 Robotnik With 1 Hit.

Unofficial codes (user found)

Code Effect
FFFE12:999D Start wing fortress(Not sure about others) with 53(i guess) lives. Super Sonic mode Presents.
016398:0100 Very short jump height.
FFB03A:11C0 Sonic Generations spindash (partially breaks the game, dying softlocks the game)
004476:00XX Player slot ID (When playing as Sonic & Tails). XX is the ID (Example: 004476:0025 changes Sonic to a ring).
00449A:00XX Sidekick slot ID (When playing as Sonic & Tails). XX is the ID.
FFF600:00YY Game Mode Modifier (YY: Mode).
  • 00 - SEGA Screen
  • 04 - Title Screen
  • 08 - Demo
  • 0C - Level
  • 10 - Special Stage
  • 14 - Continue Screen
  • 18 - 2P Results Screen
  • 1C - 2P Level Select Screen
  • 20 - Ending Scene/Credits
  • 24 - Options Menu
  • 28 - Level Select Screen
  • 8C - Pre-Level

If you want to make your own codes, see here. The format to edit those RAM values with PAR codes is this: FFXXXX:YY FF is FF, XXXX is the position of the data in RAM in four hexadecimal digits and YY is the value you want to put in in two or four hexadecimal digits. Remamber to convert your decimal value to hexadecimal first. For 2 Byte/16 bit values, put four digits in YY. If you need to enter values with four Bytes, you have to split it into two 2 Byte codes.

References


Sonic the Hedgehog 2 (16-bit)
Sonic2 title.png

Main page (KiS2|2013|3D|Ages)
Comparisons (KiS2) (2013)
Maps (KiS2) (2013)
Achievements
Credits


Manuals
Promotional material
Magazine articles
Video coverage
Reception
Merchandise


Development
Hidden content (KiS2) (2013)
Bugs (KiS2) (2013)
Region coding
Hacking guide
Bootlegs