Fantastic Game, but I was a bit uncomfortable with the music because of either the max volume or the tunes themselves but it is an issue for me and I am sure most will love this music.
I found a bug (sort of), when I was killed in Level 1 I tried to restart using the "Restart" Button but there was an error, I think you should check it, I was playing in full-screen mode If that helps.
All in all, Great Work!!