From Sega Retro
June 21 (
- 1990 - After Burner and Flash Point/Bloxeed, both CDs, are released in Japan.
- 1991 - Ganbare Gorby! and Halley Wars are released for the Sega Game Gear in Japan.
- 1995 - Panzer Dragoon Original Full Sound Version, a CD, is released in Japan.
- 1996 - Secret Codes for Sega Genesis, a book, is released in North America. StarFighter 3000 is released for the Sega Saturn in Europe.
- 1998 - Sakura Taisen 2 Dennei Kaikoroku: Dai Sei Juu Shi-nenban, a VHS, is released in Japan.
- 2000 - Omikron: The Nomad Soul and Street Fighter III: Double Impact are released for the Sega Dreamcast in North America. 4 Wheel Thunder is released for the Sega Dreamcast in Spain.
- 2001 - Head-On, and Hitori de Puyo Puyo are released for i-mode 503i compatible phones through Sega's Sonic Cafe portal alongside Cleopatra Fortune, Miss Moonlight, Pia Carrot e Youkoso!! 2.5, and Super Runabout: San Francisco Edition for the Sega Dreamcast in Japan. Sonic Adventure 2 is released for the Sega Dreamcast in Spain while Dream On Volume 22 is released in the United Kingdom.
- 2002 - Space Channel 5 Part 2 Uki Uki ★ Non Stop Mega Mix, a CD, is released in Japan.
- 2007 - Touch de Uno! DS Original Soundtrack, a CD, is released alongside Touch de Uno! DS for the Nintendo DS and Hansel to Warui Majofor EZweb (BREW 3.1) compatible phones through Sega's Sonic Cafe portal in Japan.
- 2008 - Super Fantasy Zone is released for the Wii Virtual Console in North America.
- 2011 - The arcade version of Wonder Boy: Monster Land is released for the Wii Virtual Console in Japan.
- 2012 - Power Smash Challenge Free is released for Android devices and iOS alongside K-On! Houkago Live!! for the PlayStation 3 in Japan. Mario & Sonic at the London 2012 Olympic Games is released for the Wii and Nintendo 3DS in South Korea.
- 2017 - Kid Chameleon, Phantasy Star II, and Sonic the Hedgehog are made available for the Sega Forever service for Android devices in North America, Europe, and Australia and for iOS in North America and Europe while Altered Beast and Comix Zone are released for Android devices and iOS in Europe.
- 2018 - maimai MiLK Plus is released in Japanese Arcades for the Sega RingEdge 2 board. Vectorman is made available for the Sega Forever service for Android devices in North America, Europe, and Australia and for iOS in North America and Europe.
- 2019 - Sonic X Complete Series, a Blu-ray released by Discotek Media, is released alongside Judgment for the PlayStation 4 in North America.