Ice-Pick Lodge's The Void is one of the most beautiful, atmospheric, haunting, desperation-inducing games I've ever played. It's also pretty goddamn hard to recommend for $20.
It's a fantastic, unclassifiable game, but only if you have the stomach for it: a lot of the game's charm (if you can even call it that) comes from its refusal to convey basic game rules. This would be perfectly fine were it not also for the fact that you will frequently and inescapably screw yourself over and half to redo at least a half-hour's worth of work because you misunderstood some fundamental truth about the game world.
On the one hand, this imbues every moment with a spectacular tension: if you can't understand what needs to be done to survive, if you can't understand the relationships between the different characters and the world's sole resource and yourself, you will face some pretty harsh consequences. On the other hand, it's more than a little unfair to build an entire game around intentionally vague rules, and then punish the player for not immediately understanding them.
But none of that matters, because this weekend The Void is only five frigging dollars. Even if you only play the game for an hour, the visuals and atmosphere alone will be worth the five bucks. And if you can deal with the crushing difficulty, you just might fall in love with it.