I like the art and premise
Might want to add a flash to the hit animation (both for the player and for enemies)
I didn't even realize that my projectile could do damage, I thought it just knocked enemies back to dodge them (on that note, it would be cool if you could also shoot at the enemy projectiles)
It was a lil hard to tell that the upgrade did anything, maybe change the size or color of the projectile?
I'm not sure if I finished the game, I hit a dead end room and killed all the enemies but nothing happened lol