The music kicks ass! Love the concept as well. Takes a little time to get used to but once I had it down, I actually found the game a little too easy. The enemy patterns repeat a lot and in a lot of spots their bullets will never hit so you can just stand in place and do nothing. I think mixing up the patterns and not having them mirror on both sides as much would help and put more of an emphasis on moving in and out of sync.
Also, I think the timer isn't working properly. I had it jump from like 4:59 to 4:00, 5:59 to 5:00 etc. repeatedly.