hey! this game is really polished, well-made and i love the art style! But its WAY to hard, id find myself dying constantly on the early waves, it's hard to time the punches and id often get punish really badly after barely missing a punch. The wall combo system is a really great use of the shrinking walls but doesnt get used often as i find myself being put into the wall instead of the other way around. The upgrade system is constantly: "dam, I needed that" or "dam, i can't afford that" and feels way to luck based, id recommend adding a reroll.
TLDR: Great game, way to hard and upgrade system is driven by luck.
PS, give the player a small bit of health after each round, I find myself super low on hp and i can't afford/get unlucky and cant buy a potion