(Maybe some of the critiques mentioned were addressed already but I'll post nonetheless)
I played it and got to wave 4 so I've seen all the enemy types.
First off, I think that the graphics are really cute, I like them a lot. I also really like the amount of variation in the weapons--it really keeps it interesting.
If I had to nitpick a bit, I'd say that I wish you could have more than one shot on the weapons, especially the basic gun for how much damage it does. Maybe you could have it so weapons change at random intervals instead of after each shot? Also it'd be cool if there was a "game over" screen of sorts after being killed by an enemy (at the moment, your character disappears but the game continues)
Overall I liked it a lot, a really fun wave-based shooter.