Terraforming!

So I was reading Freefall, a fun little comic which I have been following recently, and they started talking about terraforming.  I instantly remembered how fun it was to play SimLife back in the 90's.  Wow...  How cool would it be to have a modern game, where you had to manage all aspects of an ecosystem?  I don't mean like Spore, which was such a failure of a game in my opinion.  But I mean a full fledged, complex game, involving possibly hundreds of different plants and animals which all work together symbiotically to create a smoothly running ecosystem.

How great would that be?  First you start off with a barren rocky planet...   you have to generate an atmosphere, and use microbes to create oxygen.  And you move slowly up from there, allowing creatures to evolve, or adding new creations yourself, all while maintaining the stability.  Create small 'dots' of terraformed land, and watch how it spreads if it does well, and see what plants survive better, and as the soil increases watch other plants take over.   Fricken amazing!