Antichamber is half off on Steam through April 18 at 4 p.m. PT, bringing the price of completely blowing your mind to $10. What a steal. Antichamber has already "absolutely, exponentially" made back its production costs for developer Alexander Bruce, but a Steam sale never hurt anyone.
In more psychological Steam news, IGF nominee Starseed Pilgrim is out now to teach you how to tend the seeds of the universe. You little gardener, you. Starseed Pilgrim is $6, now and forever, for PC and Mac.