only two things of real bad note for me:
- since invincibility can go through enemies and damage has a small pop out, the player can keep popping out inside of an enemy and just get trapped. not a big deal in normal play, but i'm trying to speedrun, which means not killing enemies, and from there you get the idea.
- escape button. i personally kept pressing escape at first to pause the game to reset (obviously not the controls but i'm used to osu), and i got annoyed pretty quickly when it just closed the game.
otherwise, clean concept. unique, well thought out, and well executed.