Anniversaries/September 9
From Sonic Retro
September 9 (add)
- 1998 — Issue #138 of Sonic the Comic is released in the United Kingdom.
- 1999 — Sonic the Hedgehog: The Movie, a DVD, is released alongside Sonic Adventure as one of the launch titles for the Sega Dreamcast, as well as Issue #30 of the comic series Knuckles the Echidna in North America.
- 2002 — Sonic Golf C-Mode Cup is released for i-mode 503i compatible phones through Sega's Sonic Cafe portal in Japan.
- 2009 — Sonic & Knuckles is released for the Xbox 360 worldwide.
- 2010 — Issue #20 of Sonic Universe is released in North America.
- 2015 — Issue #276 of the Sonic the Hedgehog comic series by Archie Comics is released in North America.
- 2017 — "Vector Detector", the 96th episode of Sonic Boom, airs in North America.
- 2021 — Sonic Colours: Ultimate is released for the PlayStation 4, Nintendo Switch and Epic Games Store in Japan, South Korea, and Taiwan.