It’s highly unrealistic to try to even store a single full-sized galaxy (so not even talking about trying to simulate anything in it), because if we assumed that each solar system could be stored with just 32 bytes of information (which is basically not enough for anything more than just a few star properties and a couple of planets with no life whatsoever) then it will take terabytes of storage per galaxy. So Thrive saves would be terabytes in size in the space stage. That’s just completely impossible.
I’ve previously talked about this here: