Sonic Generations (ソニック ジェネレーションズ, Sonikku Jenerēshonzu) is a platform video game, developed by Sonic Team and published by Sega for PlayStation 3, Xbox 360, and Microsoft Windows. The Nintendo 3DS version of the game was developed by Dimps. Released in November 2011 in North America, Europe and Australia and in December 2011 in Japan, the game commemorates the 20th anniversary of the Sonic the Hedgehog series.