Hammerwatch (3-pack) | Humble Daily Bundle | £4.76 (RRP: £20.99!)
This Gauntle-inspired hack and slasher is a proper laugh with mates, and properly cheap too if you get involved as a foursome. Hammerwatch usually retails at £6.99 or £20.99 as a three-pack, yet until 19:00 this evening, you can snag four copies for a very competitive £4.76. Big savings.
Thanks to targetbsp for pointing out that you get four copies as opposed to three in the comments - since you get the game and a triple gift pack.