http://www.pcgamer.com/the-amnesia-collection-is-free-on-the-humble-store/

The Humble Store is offering a sweet deal on two of the most frightening, disturbing videogames ever created. For the next two days, the Amnesia Collection—The Dark Descent and A Machine For Pigs—is completely free. 

Amnesia: The Dark Descent is famously scary, to the point that it became staple fare for reaction video freakouts on YouTube. It's an utterly crushing, physically and emotionally exhausting experience that somehow manages to keep getting worse, almost to the very end—and I mean that in an entirely complimentary way. A Machine For Pigs is very different—creepy, disturbing, but more cerebral than in-your-face, and almost certainly a better candidate for a replay.