Sonic Generations is a
singleplayer
platform
game in the Sonic the Hedgehog series developed by Sonic Team and published by Sega. The game is intended to be a celebration of the 20th anniversary of the Sonic the Hedgehog franchise, with it featuring the play-styles and character designs of two different eras of Sonic ("Classic" and "Modern") and stages based on various games from the franchise spanning 1991 to 2010.