Kerbal Space Program seems like something I could either sink a lot of time into, or play for 5 min. and then never play again. I've had it in my wishlist for forever and I'm still waiting for a big enough discount.

I'm kind of in between games atm. I've played about an hour of Shadow Warrior, which didn't seem like the game I would like but it was 90% off, so I got it anyway. it's super fast paced first person sword fighting with very good mechanics, and it looks gorgeous. I have weird performance issues so I probably won't finish it. What I'd really like is another Game like the most recent Tomb Raider to pass the time until Legacy of the Void gets released.