I have never played the psp version/s, so I have no basis for comparison, but I love the ps2 version. The game is fun, the music is cool, its just well made overall. But then again Im a big puzzle game mark.
The only real criticism that Ive read is that this game in exactly like the psp version, and that theres very little extra to warrent the 'plus' in the name. But since its all new to me, that criticism means nothing.
If you dont have a psp, and you like puzzlers, you cant go wrong with this for $20 or less.