Not the best
There are three different single player game modes. Story mode is where you pick a car and use it for 11 different levels to destroy the other people's cars. Challenge mode is where you make all the rules and choose the opponents. Endurance mode is where you see how long you last. There is also a multiplayer mode for this game.
The characters from all the old games are back like: Sweet Tooth, Axel, Warthog, Outlaw, and many more. Each have their own characteristics (speed, armor, special weapon, and handling). There's bound to be a character for everyone.
This game is a fun game and an easy game to learn so I recommend it for people just getting the PSP also. Some people may not like the game so I recommend renting it first (gamefly.com *Please Refer Me).