From Sega Retro
Double Dragon (ダブルドラゴン) is a 1987 arcade beat-'em-up by Technos. It was ported to a variety of consoles; Accolade brought it to the Sega Mega Drive in 1993 and Sega to the Sega Master System in 1988. Accolade's version was licensed by Sega, despite the ROM header saying otherwise.
The game takes place over four levels ending at the final boss, Willy. The first player is Billy and the second controls Jimmy. The characters are able to punch (), kick (), and perform a variety of moves by using combinations of the available buttons. The Mega Drive version has a jump button () while the Master System version only allows jumping through button combinations. Weapons found throughout the level can be picked up and used against opponents. Weapons that can be used include bats, whips, barrels (not in Master System version), boxes, rocks, knifes, and sticks of dynamite.
Levels include a slum, a industrial area, a forest, and the boss's lair. Level hazards include pitfalls, water, conveyor belts, poles which come out of walls (not in the Mega Drive version), and spikes.
The Mega Drive port is a straight port of the arcade with slight differences in graphics and sound. The enemies also easily mimic the players up and down movement, which can lead to some annoyance.
The Master System version has slightly different controls due to the controller only having two buttons. Some parts of the levels are designed differently and extended. The mohawk Abobo is missing in this version. Unlimited continues are available up until the final stage (although unlimited continues can be attained in the final stage through a cheat).
Master System version, while graphically more impressive than most other ports (NES for instance) it is generally considered inferior due to removed parts which actually made the game shorter. It is also one of the few two player action games that exist for Master System.