In SimEarth you will enjoy being in charge of a planet throughout it's 10 billion year life. The ultimate goal is to control the planets inhabitants from their single-celled birth to their star-like death.
There are many threats you will face throughout the game. From pollution, famine, disease, war, and global warming. You have all the controls you need to change the game from moving continents to mountains. You can create different levels. Activate earthquakes and tidal waves. Everything you do takes energy so be wise with what you spend it on.