I love this game/simulation!

I think that most of these reviews have good ideas, so instead of restating Ill say look below. Also my suggestion is that there should be 2 or 3 levels of complexity, mostly for sandbox mode (I dont know how to work it into survival). That way you can do level 1 to get the feel for it, 2 to get going, and 3 to really challenge you.

Kaizen216 about Artificial Life