I know there are some gamers on here, since they've mentioned it. So ... why not a thread for it?
I'm currently playing
Craft the World. It's a rather endearingly insane combination of Minecraft, a generic tower defence game, and the legendary Dwarf Fortress.
Campaign mode currently has four worlds of increasing difficulty, and each with their own challenges regarding resource management. Sandbox mode is, to me, less interesting. Be warned, though, it's a time sink.