And you can play God Games too! The SIMS are nice, but limit your godhood to a single environment on a single planet. To get into the game from a Universal level, try Discover’s Star Formation. You start with a dust cloud, and set up conditions to optimize star creation as gravity nodes gather mass. Another fun one is the Universe Sandbox, where again you start with the basic laws of physics, and modify the parameters to create your desired results. For a Gods-Eye view of the universe, you can try World Wide Telescope, the Windoze ripoff of the classic Open Source monster Celestia. And if you like the Open Source version better, be sure to visit Celestia Motherload, with a ton of upgrades and plugins, including the Selden Ball data.