Costume Quest 2 and Layers of Fear 2 are free for a limited time.
Costume Quest 2
Explore spooky time-traversing landscapes, don adorable new costumes that transform into powerful Hallo-warriors, and collect even Creepier Treat Cards to wield in combat against a legion of hygiene obsessed baddies.
Layers of Fear 2
Layers of Fear 2 is a first-person psychological horror game with an emphasis on exploration and story. Players control a Hollywood actor who heeds the call of an enigmatic director to take on the lead role in a film shot aboard an ocean liner.
via Lysander at OzBargain