Fun game! The art style is nice and the gameplay is simple but fun. I did find some areas that would be good to polish, e.g. the level transitions are quite jarring (not changing the color and interpolating or tweening to the new view would be nice). But the gameplay is fun and I like that there's some variety in the enemies, e.g. the normal ones are standard but the bigger ones have different priorities. I'm reminded of the talk from the creator of Plants vs Zombies on making enemies feel different (having trouble finding it on YouTube though).