I enjoyed this game, It reminded me of the flash games of yore, just with less jank. Well done. The game was easy to pick up and fun to play. It did feel a little floaty at times. (Specially when the enemies "jump" on each other and fly into the sky.)
I got the wave 8 and I found the difficulty curve sort of tapered off. The first 3 waves are easier but then wave 4 and 5 seem to be just enough enemies to come at you and regularly enough to make it tricky to dodge them. After wave 5 though there are so many enemies they all start bunching up and the player can just mash attack and make short work of them. I think if the enemies were a little more spread out that would improve it.
I played on Mac and the game was buttery smooth, I didn't have audio, but I am not sure if that is a bug or not.
Well done that was a great game. I enjoyed it.