Cool music and art. I also thought the game was pretty fun.
My feedback would be that the UI is too big and the game is too easy. I suggest you making it harder to heal because I found I could survive perfectly fine just sitting in one spot and killing all of the enemies near me. Also putting a boundary in the game, so the player can't just run away when in a tight spot.
Another suggestion is that along with the different random powerups, you could add something that would change the rhythm you need to click to get the crit so that you aren't clicking repetitively. Something like changing it to the off-beat or having the player need to do triplets or something.
Also sometimes the turret enemies would stop shooting for a bit. I don't know if this is intended or a bug.