This is a really cool game. I really like how you introduce new game mechanics with every level. This way you learn the game without a tutorial. Of course the first few levels are kind of tutorials, but it does not feel like that. You feel very smart when you solved these levels :D. There is not much to improve, maybe the music gets a bit repetitive after a while and the art style is very basic. On the other hand the art style also fits the game which is more abstract and does not need fancy art.
Congratulations to this amazing game!