Best aspect is the use of mouth-generated sounds.
The controls are awkward as hell if you want to do anything with it. Instead of making it so you click the drums, make it so you press keys. Much easier to switch between sounds that way. The art is quite bad; I'd say really take a good hard look at a drum kit next time you draw one.
Though the cymbal DOES sound pretty bad, and I think you could do better, I honestly think the fact that you made the drum sounds with your mouth is kind of neat.