The gloves are off and Sonic and his rivals are gearing up for an intense new head-to-head competition exclusively on the PSP(PlayStation Portable) system. This sequel to Sonic’s 2D action platformer features all-new "jostling" controls for tighter competition and a brand-new Battle mode that allows two players to jump into six different Multiplayer challenges by sharing one disc. With three new characters, 12 new stages, and upgraded signature moves for each character, the enhanced Rivals experience will bring a whole new level of handheld fun to the PSP system. Features: Battle Mode: players will select from six ways to thrash their rival buddies: Knockout, Ring Battle, Race, King of the Hill, Capture the Chao, and Tag. Single Disc Game Sharing: two players will easily access the Multiplayer challenge with just a single disc using the wireless function. Intriguing New Storyline: the Chao seem to be disappearing and all eight rivals must work fast to find out who is behind it. Three New Playable Characters: Miles "Tails" Prower and two other new characters round out the cast of eight rivals. Free Play Mode: free from rivalry, the player can experience the challenging old-school Sonic-style map at their own pace! Expanded Card Collection: players can now collect 150 new cards for loads of new options to customize their playable characters.