PlanetPop!

You control a little space ship, and you've got the ability to fly wherever you'd like to. The world generates new planets, and your goal is to populate as many of them. You collect space rocks using a vacuum, then craft buildings which you can plop down on the planets. You can also craft a mine which will generate you rocks until the planet has ran out. If a planet is populated enough, the inhabitants will start to seek out to other planets by flying with mini spaceships.