The meat of the game is the Rags-2-Riches mode, which attempts to simulate a reality TV show where a no-name baller makes his name on courts against NBA stars. In truth, it's just another ladder tournament with unlockable skills, items and so forth. But the framework is a good one, especially since the character creator is solid and the increasingly difficult tournament events will challenge most players.
The primary problem with Rebound, especially if you're migrating from the PS2 version, is the reduced control set of the PSP. Without a second analog stick, your juke selection is limited to a random sampling of moves; the same 30 jukes are still possible, but there's no control over which will occur when you actually tap the button. Repetition can set in fast. The basic controls are rock solid; the details just aren't as flexible as before.
And due to the reduced storage space of the UMD disc, there's also not as much stuff to unlock. (We'll also blame the UMD at least partially for the excruciating load times.) New players will never notice, but we'd have preferred Midway to lose some of the music (who keeps streaming music turned on in PSP games, anyway?) and keep all the unlockables. The two PSP exclusive courts and new modes like Dunk Fest almost make up for them, but not quite. The game is about bling, after all.