SimEarth: The Living Planet

SimEarth is the second life simulation video game designed by Will Wright, in which the player controls the development of a planet. The game was published in 1990 by Maxis.

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. Since it is a software toy, the game does not have any required goals. The big (and difficult) challenge is to evolve sentient life and an advanced civilization. The development stages of the planet can be restored and repeated, until the planet "dies" ten billion years after its creation, the estimated time when the Sun will become a red giant and kill off all of the planet's life.