Cool game ! However having to wait several seconds to switch sizes is extremely annoying imo, pair that with the lasers that appear without much warning and you got a recipe for an extremely frustrating experience (It's to the point where I wanted the game to end after 2 levels), though, this is just personal preference. Other than that, it would have been nice to have some sound effects along with the music (Which is really cool btw). Overall, it's a pretty good game !
Edit: Oh and I forgot to mention that the timer is pretty hard to notice, it took me a solid minute to realize its existence in the first level.