Sonic Rivals is a platforming/racing game that features on the PlayStation Portable. It has typical Sonic gameplay, but with a twist - players race through 2.5D stages against a CPU character, only progressing when they get to the end of the stage first.
You can choose from five characters: Sonic , Knuckles, Shadow, Silver, and Metal Sonic . There are six zones in the story mode, split into two acts with a boss at the end of the second act. Defeating bosses is not sufficient, players also need to do it before the opponent gets the job done. Next to the story mode, there is also a challenge mode and a cup mode. In the wireless play mode players can challenge other PSP owners. While racing, players can collect power-ups with special attacks. Opponents can also be pushed around during the race.
Players can also collect cards by completing certain tasks in the game and these cards can be traded in the wireless play mode.
Sonic Rivals was released on December 1st, 2006 for the PlayStation Portable.