It has a really nice gameplay, yet it's very simple if you played at least one good rhytm game before. On the hardest difficulty i had no problems whatsoever. The Main Character - Chai - is pretty annoying, but mostly in the first half of the game. Other characters are pretty nice.
The story is cartoon-simple and it's not bad.
Music is nice, but i can't say it's something memorable, at least not for me, though it has some nice soundtracks. That level with The Prodigy stole the whole show though, maybe this is the main reason.
On the bad sides - sometimes game checkpoints are placed weirdly. I really hated it when after failing a battle, i had to listen to an unskippable dialogue and cutscene all over again.
Also sometimes i felt like levels drag for too long, which i find really weird, because after beating one i thought "It only took 50 minutes? I swear it felt like 2 hours" or something like this.
Anyway, i definitely recommend this game to everyone.