FTL: Faster than light
An amazing roguelike game that instead of placing you in a dungeon full of trolls and whatnot, gives you a space ship with a crew and a randomly generated universe to explore. And for only 10$!
The game is brutal and unforgiving, but so fun. I managed to defeat the alien mothership for the first time yesterday, only to die 20 minutes later due to uncontrolled fires - my crew was too badly wounded to contain them, they did damage to all critical systems including the life support which made my crew suffocate. I could have locked them in a single room and vented the atmosphere from the rest of the ship to extinguish the fires, too bad I didn't think of it then