Sim Earth - The Living Planet
In SimEarth, the player can vary a planet's atmosphere, temperature, landmasses, etc., then place various forms of life on the planet and watch them evolve. In the “Random Planet” game setting, the game is a software toy, without any required goals. The big (and difficult) challenge is to evolve sentient life and an advanced civilization, culminating in that species leaving the planet in an exodus.
