This is a really cool idea! I like the mix of whack-a-mole style gameplay with a musical puzzle. I managed to break the game unfortunately- the countdown got stuck at 24 and the ghosts stopped appearing. Hitting rewind started the background music again, but the enemies didn't reappear. I suspect part of the problem is playing the game on a laptop- I had to scroll up and down a lot to see the whole screen, which involved clicking off the game. Nonetheless, I think it is fun and look forward to seeing what you do next :)