Lovely game, the artstyle is very cute and with the best implementation of the theme so far. Love clumping asteroids together so that I can grab multiple at once. The bosses are really cool, I love the black hole sucking everything in space and you can't really grab asteroids because the pull is to strong and you just have to avoid getting eaten. My only nitpicks is that the game could use some SFX, I think you've went with sound doesn't travel in a vacuum approach, but I feel the need of some auditory feedback to know that I've been hit and that I am hitting the boss. And also the planet feels very slippery at times, which makes dodging some attacks of the black hole quite hard.
Besides that, this is a pretty cool game which I would love to see it grow in the future.