I'll have to admit that Ancestors had me a bit confused simply by how much it threw at me in such a short timeframe. It's got one busy HUD. Historically speaking, I can understand how the game could work as an educational reference on the subject of evolution. Creationists may want to avoid for political reasons.
I can't say I have enough patience to play the game long-term, and it baffles me that my character is freaked out by so many things in the dark. Maybe I would be, too - or I wouldn't know what to be scared because I didn't know what was there to begin with. The logical conundrums of our primal ancestors.