no worries Nick!
thanks for getting back so quick.
here's some other random advice I would give. the difficulty seems impossible past the 6th wave or so, so i would add some features that would fix this.
A idea I had was power-ups that flew across the sky and you had to hit with your axe. they give you abilities, such as instant recharge, axes that go through enemies, or multiple axes at a time.
any other way of making the games last longer for a skilled player would be cool though.
overall, I think the art and sound are great in this game, and the mechanics are simple but difficult. don't take that away
hope that's helpful