Very fun and SLICK idea! I would've loved to see the slick haircuts before the enemies disappeared. I would suggests decreasing the size of the hitboxes from either the player or enemies since there were occasions where I was at least a few pixels away but still took damage. Adding i-frames would be great too to avoid taking damage from multiple enemies at the same time to make this less difficult. I made it to wave 10 with 1 HP and died immediately when an enemy spawned on me... All minor tweaks. I can definitely see this being built out further! Great job!