first off i have to say the art is awesome. and i love the sound and music. so big thumbs up!
my main problems with the game are,
the controls are not very common and its hard to figure out the buttons i need to press, but with time i did get use to it.
and i do really wish you would add more time to hit the notes, it feels ever so off.
and lastly its hard, sometimes unfair. but that's not always a bad thing. some editing and i think you would have a very good game, some would even pay money. :)