I think it's a cool start. Does the game parse through the sound's amplitude or something to determine how to react or what?
First I think you could make the background less seizurely by having it slowly change rgb values to fade between colors or something. I'm sure you could do a lot more with the bg too but atleast make it easier on the eyes first haha.
Next it'd be nice if getting hit didn't end the game, and instead just lowered your score and played the "missed note" sound kind of like how they do in Guitar Hero and Rock band. Maybe if you miss a certain amount or too many over a span of time you'd lose, but right now it's too harsh and frustrating.
Maybe if I barely dodge one of the enemies I get an extra "close call" score bonus like in some racing games.