The Cell Stage is short but enjoyable enough. The Creature Stage is really basic but it's oddly charming. The Tribal and Civilization Stages are pretty much baby's first RTS. I've always enjoyed them personally, but neither is very interesting.

The Space Stage and Creature Creator are no doubt the focus of the game. Creating creatures is cool, and I think making them more complex as you progress in the Creature Stage and seeing how they've changed at the end is the best part. Space Stage is a bit mixed. I think it can be enjoyable and there are things to do, especially if you get the Galactic Adventures DLC, but I don't think it manages to hold my attention for as long as it should. I've played through the game many times, telling myself I would beat Space Stage each one, and I never did. I know that it doesn't really have an ending, but there is sort of a goal, and I could never bother to reach it.

All in all, enjoyable enough, I suppose.