OMW, I absolutely love the music and simplicity of the game! Really easy to understand, yet hard avoid all the obstacles.
I will say that the energy drains to fast in my opinion. I think this could be resolved with slower draining or only draining when aiming. Also the music volume slider doesn't work but personally I don't mind as I was grooving to it the whole time!
Edit: I was playing it in the web browser when having the volume issues but it works in the downloaded version so maybe it was just my browser being dodgy?