I have a few small things I didn't like that much. First of the Hit boxes of Black Holes are to big and feel unfair, you should make them a little bit smaller. Second of all the Planets are spawning in on the top of the screen so you can see them when they are destroyed and spawned in, it would be cooler if they are destroyed after they left the screen and instantiated before they enter the camera view. Besides that very cool Game and really nice soundtrack , over all really well done :D