This was a blast to play and a great idea for a rhythm based game!
I think if you polish this game some more you could have a really good thing going!
Only two issues:
1. The spikes are a little hard to see because I'm so focused on the red dot (this may have been due to my screen size or something but wanted to share).
2. The game just sort of ends for me. Not sure if this is a bug in my browser or something else.