Amnesia: The Dark Descent is free on Steam until Wednesday
And free to keep. Not free to play for a few days.
Once you have downloaded Amnesia: The Dark Descent, head over to the storefront and take advantage for the 80% off sale on the Amnesia and Penumbra franchises. The sale ends on Friday.
Amnesia: The Dark Descent is free only until Wednesday at 10am PT/1pm ET/6pm UK so at least get it in your queue.
Frictional Games' upcoming horror game SOMA is also 10% off when you pre-order. It's out on September 22.