Terraria in space. Procedural planets with procedural plants and procedural inhabitants in a fairly massive galaxy.

http://playstarbound.com/

http://www.youtube.com/watch?v=rsjy7d_GVqE&feature=c4-overview&list=UUgy-XzXwcdJKNKIUyzQmw7Q

http://www.youtube.com/watch?v=SR1JsXnQnTQ

This is pretty cool. And apparently interstellar spacecraft run on steam engines :D