Simple mechanis but good realisation!
I really liked:
VIsual style - things are drawn good, also lighting makes everything look grate!
Gameplay - challenging yet satisfying when you are able grow :D
The only suggestion I have is to make black holes smaller mayber: they appear suddenly, move fast, and take up a lot of space, so sometimes I barely have time to react - and the result is really punishing, you need to replay:( But maybe its my problem and it was made intensionally.