Guacamelee! Super Turbo Championship Edition Is Free on Humble Bundle

multiplayer on this is SO MUCH FUN.

highly recommended. Get in on this! Give the humble people some money while you're at it!
This is also free via the Steam store until 5/23, too:

(When you click on the link it'll say 100% off)
Guacamelee 2 is also heavily discounted. Never played that one, so I bit. The first game is a total blast. I played it on the PS Vita and this version feels a lot bigger than I recall. I think the Super Turbo DLC stuff really fleshes things out.
FYI, Guacamelee 2 is TOUGH. The first dungeons have areas that are as hard as the toughest challenges in the first game. If you like that game (especially while it was free), it's worth the purchase.