Sonic Rivals feels like they just made a game so they could have a Sonic game on the PSP. It's just racing to the end of the levels with no real complexity in the level design. Some parts of the game are frustrating, however I wouldn't say any parts are outright bad. The story also just makes little sense, and the way they try to tie in why you're competing against these characters just never really works. Overall, while Sonic Rivals is not a bad game, it isn't exactly one worth playing all that much.