Sonic Generations is a platform game in which players control two variants of Sonic the Hedgehog: "Classic" or "Modern".[2] Classic Sonic's gameplay is restricted side-scrolling gameplay similar to the original Sonic the Hedgehog games released in the 1990s,[3] and requires him to use moves such as the Spin Dash and the Spin Attack.[4] Modern Sonic's gameplay follows the gameplay style of Sonic Unleashed (2008), and Sonic Colors (2010),[5] featuring an amalgamation of third-person and side-scrolling perspectives and techniques such as boosting and homing attacks. Both Sonics collect rings as a form of health,[6] and power-ups such as elemental shields, invincibility, speed shoes, skateboards, or Wisps. Players can also customize each Sonic's abilities, and purchase additional ones at a Skill Shop.[7][8]
The game's main hub is a realm called White Space, in which the player can explore, converse with other characters, and access the game's levels, each of which are derived from a previous entry in the series.[9][10] The levels are split into three separate eras: the Classic Era (focusing on levels from games for the Sega Genesis);[11] the Dreamcast Era (focusing on levels from games for the Dreamcast, PlayStation 2, GameCube, and Xbox);[12] and the Modern Era (focusing on levels from games for the PlayStation 3, Wii, Nintendo DS, and Xbox 360).[13][7] Each level consists of two acts (one for each Sonic), and ten additional missions such as collecting a certain amount of rings or completing a level with the help of another character.[14]