Spore prototypes.

I, for one, like the "Space" prototype's terraforming system. Sure, the "climate" part is way simpler than Spore's (it's more like the original 2005 idea) but the biosphere portion builds the illusion that there are solid biome mechanics (when it says what elevation a plant prefers, it really just tells what atmospheric pressure they survive best at, so the "biomes" pretty much create themselves).