Anniversaries/March 15
From Sonic Retro
March 15 (add)
- 2007 — Sonic to Himitsu no Ring is released for the Wii while Sonic Darts is released for EZweb (BREW 2.1) compatible phones though Sega's Sonic Cafe portal, both in Japan. Seven Rings in Hand: Sonic and the Secret Rings Original Sound Track, an album, is released on CD in Japan.
- 2010 — Sonic & Sega All-Stars Racing is released for the Xbox 360, Wii, and PlayStation 3 in Russia.
- 2012 — Sonic the Hedgehog Triple Trouble is released on the Nintendo 3DS Virtual Console in North America.
- 2022 — Sonic the Hedgehog: The IDW Collection 2, a book, is released in North America.