Anniversaries/September 18
From Sega Retro
September 18 (add)
- 1989 - The cassette version of Shinobi is released for the ZX Spectrum in the United Kingdom.
- 1992 - Shadam Crusader: Harukanaru Oukoku is released for the Sega Game Gear alongside Roppongi GiGO, the first GiGO game center, opening in Japan.
- 1993 - Sonic the Hedgehog, also known as SatAM, begins airing in North America.
- 1996 - Space Hulk: Vengeance of the Blood Angels is released for the Sega Saturn in North America.
- 1997 - DoDonPachi, My Dream: On Air ga Matenakute, Pachi-Slot Kanzen Kouryaku Uni-Colle'97, Soviet Strike, and Street Fighter Collection are released for the Sega Saturn in Japan.
- 1998 - Sakura Taisen: Ouka Kenran Hikari Rokuonkan, a CD, is released in Japan. Deep Fear is released for the Sega Saturn alongside Enemy Zero for Windows PCs in Europe.
- 1999 - Climax Landers Perfect Guide, a book, is released in Japan.
- 2000 - Sentimental Graffiti 2 Koushiki Complete Guide, a book, is released in Japan. F355 Challenge is released for the Sega Dreamcast in North America. Walt Disney World Quest: Magical Racing Tour is released for the Sega Dreamcast in Australia.
- 2001 - NFL 2K2 is released for the Sega Dreamcast in North America.
- 2002 - Napoleon is released for J-Sky (50KB) compatible phones through Sega's Pocket Works portal in Japan.
- 2003 - Sakura Taisen OVA: École de Paris Hikari Rokuonkan, a CD, is released in Japan. Kid Chameleon is released for RealOne Arcade in North America.
- 2004 - J.League Pro Soccer Club o Tsukurou! '04 Final Playing Guide, a book, is released in Japan.
- 2006 - Virtua Pro Football and Yakuza are released for the PlayStation 2 alongside Phantasy Star Universe for the PlayStation 2 and Windows PCs in South Africa.
- 2007 - Super Thunder Blade is released for the Wii Virtual Console in Japan. Sonic Rush Adventure is released for the Nintendo DS in North America.
- 2008 - Rambo is released in Japanese Arcades for the Sega Lindbergh Red EX board. PictoImage is released for the Nintendo DS in Australia.
- 2009 - Let's Tap: Tap Runner is released for iOS in Japan. The Arcade version of Golden Axe is released for the Wii Virtual Console in Europe.
- 2012 - Jet Set Radio Original Soundtrack, a CD, is released alongside Empire: Total War Gold Edition for the Mac App Store in North America. Empire: Total War Gold Edition is released for the Mac App Store in the United Kingdom while Jet Set Radio is released for the PlayStation 3 in Europe.
- 2013 - Sega confirms that it has taken over the operations of Index Corporation, and with it, the ownership of the company Atlus.
- 2014 - maimai Orange is released in Arcades for the Sega RingEdge 2 board alongside Puyo Puyo Fever Rhythm for Android devices through Sega's Puyo Puyo! Sega portal in Japan.
- 2018 - Yakuza Kiwami 2 is released for the PlayStation 4 in Europe and Australia.
- 2019 - Babel no Medal Tower W, a medal game, is released in Japanese Arcades.