Lovely art and soundtrack, and very cool idea! I found it to get pretty punishing pretty early on - might have helped to get half a second of invulnerability each time you get hit, or start with slower music / wider gaps and then ramp up.
Yeah, definitely, there is an invulnerability window built in, but it is definitely too short. And there should be easier levels at the beginning.Thanks for the feedback, especially the constructive part :)
