Zorb.io has one of the best graphics and is one of the most educational space game ever to have been made. The experience of this 2D game comes out so that its better than a 3D version. Just as black holes in our galaxy and other galaxies, you eat the sorrounding mass near your orbital route. However, you’re not bound to movement, you may operate in 360 degrees around your own axis. However, be aware that just as postulated in theorems, larger black holes may consume you if you re close enough. So, make sure you re out of the orbit of other planets and other nasty things.
The main objective of the game is to consume the orbitals and flow through outer space as you get bigger. This game also has been coded so that smaller planets may gain mass from bigger planets.