Jazzpunk, from Humble Weekly Bundle: Extra Life 2015 (Yes, 2015.. That's not a typo! I'm clearing out more old unredeemed duplicate games, from Humble Bundles).

Once in awhile (I've only had it happen once, out of 60 giveaways), an old Humble key is rejected, and they won't help me get a new one. If in the VERY unlikely event that happens, please be kind enough to agree to deleting this giveaway.