...is awesome!
http://www.kerbalspaceprogram.com/index.phpBasically you're in charge of a space program. You build a rocket and pilot it and try to achieve milestones you desire. It's entirely sandbox for now, so you can freely experiment without money, time or goal constraints. So far I've successfully went beyond 1000km in height, and even did one flight with a partial orbit of the planet and touched down.
Be warned though, it's harder than it looks, especially when the rocket starts spinning out-of-control or starts to fly erratically due to an inelegant design, or even a slight maladjustment at the wrong time with the controls.
