I like the art style and the idea behind it. I only found two things that I dislike :
1. When you view controls, you can't go back using the escape key, it's a little annoying when you are familiarizing with the controls.
2. You can't change back your weapon, it's only 3 but it looks like a fast paced game, so change back and forth would help.
I personally think that with those things the game would be even more fun, but it's a really awesome game!
Oh, and I saw a enemy stuck between a tree and a rock. Maybe you could use some raycast or pathfollow to help the enemies with that?