From Sonic Retro
December 1 (
- 1992 — Sonic the Hedgehog 2 is released for the Sega Mega Drive in Australia.
- 1999 — Issue #79 of the Sonic the Hedgehog comic series by Archie Comics is released in North America. Issue #170 of Sonic the Comic is released in the United Kingdom.
- 2004 — Sonic Darts is released for J-Sky (50KB) compatible phones through Sega's Sonic Cafe portal in Japan. Issue #143 of the Sonic the Hedgehog comic series by Archie Comics is released in North America.
- 2006 — Sonic Rivals is released for the PlayStation Portable in Europe.
- 2011 — History of the 1st Stage Original Soundtrack Blue Edition and History of the 1st Stage Original Soundtrack White Edition, both CDs available only to those who preordered Sonic Generations, are released alongside Sonic Generations: Shiro no Jikuu for the Xbox 360 and PlayStation 3, Sonic Generations: Ao no Bouken for the Nintendo 3DS, and Sonic Advance for Android devices through Sega's Puyo Puyo! Sega portal, all in Japan.
- 2017 — Sonic Forces is released for the Nintendo Switch in South Korea.