Anniversaries/May 31
From Sega Retro
May 31 (add)
- 1991 - The Teradrive is released alongside Puzzle Construction, as well as Fire Mustang and Zero Wing for the Sega Mega Drive, and Ryukyu for the Sega Game Gear, all in Japan.
- 1994 - Triad Stone is released for the Sega Mega LD in North America.
- 1996 - Godzilla Rettoushinkan Koushiki Guide Book, a book, is released alongside Sonic the Hedgehog Part 1 and Part 2 and Virtua Fighter: TV Animation Series Vol.1 and Vol.2, both VHS, as well as Defcon 5, Dragon Ball Z Idainaru Dragon Ball Densetsu, Sword & Sorcery, and Wizardry VI & VII Complete for the Sega Saturn, all in Japan. Striker '96 and Virtual Open Tennis are released for the Sega Saturn in North America.
- 1998 - MeltyLancer Re-inforce Official Guide, a book, is released in Japan.
- 1999 - Elemental Gimmick Gear Koushiki Complete Guide and Get Bass Fishing Guide, both books, are released in Japan.
- 2000 - Cyber Troopers Virtual-On: Oratorio Tangram M.S.B.S. Ver. 5.4 is released for the Sega Dreamcast alongside the GameShark CDX for the Sega Dreamcast in North America.
- 2001 - Segagaga Perfect File, a book, is released alongside Crazy Taxi 2, Exodus Guilty Neos, and the retail release of Segagaga for the Sega Dreamcast and Hundred Swords for Windows PCs in Japan. Worms World Party is released for the Sega Dreamcast in North America. 18 Wheeler: American Pro Trucker and Confidential Mission are released for the Sega Dreamcast in Spain.
- 2002 - Saka Tsuku 2002: J.League Pro Soccer Club o Tsukurou! Senshu Meikan, a book, is released in Japan. Super Monkey Ball and Virtua Striker 3 Ver. 2002 are released for the Nintendo Gamecube in France.
- 2003 - Dennou Senki Virtual-On Marz: The Complete Guide, a book, is released in Japan.
- 2004 - Sonic Underground Vol.1 and Vol.2, both DVDs, are released in the United Kingdom.
- 2006 - Billy Hatcher and the Giant Egg is released for Windows PCs in Europe.
- 2007 - Shining Wind Music Collection, a CD, is released alongside Guilty Gear XX Accent Core and Jissen Pachinko Hisshouhou! CR Aladdin Destiny EX for the PlayStation 2, as well as Zunzunkyou no Yabou for EZweb (BREW 3.1) compatible phones through Sega's Sega Ages portal in Japan. Crush is released for the PlayStation Portable in Australia.
- 2012 - WCCF 10-11 Senjutsu & Data Book Ver. 2.0 Taiouban, a book, is released alongside Jissen Pachi-Slot Hisshouhou! Hokuto no Ken F: Seikimatsu Kyuuseishu Densetsu for the PlayStation 3 in Japan.
- 2013 - 7th Dragon 2020-II Complete Guide, a book, is released in Japan. Warhammer 40,000: Dawn of War II: Retribution and Warhammer 40,000: Dawn of War II: Retribution - The Last Standalone are republished on Steam by Sega.
- 2017 - Crazy Taxi Gazillionaire is released for Android devices in North America, Europe, and Australia and for iOS in North America and Europe.
- 2023 - Etrian Odyssey HD, Etrian Odyssey II HD, Etrian Odyssey III HD, and Etrian Odyssey Origins Collection are released on Steam in Japan, North America, Europe, Australia, South Korea, and Taiwan.