This is easily the scariest game I've played this gen. Scarier than Amnesia, Cry of Fear, etc. Slender: The Eight Pages may have been an overly simple game that earned a bad reputation from Youtube screamers, but this game is legit. I'll likely do a full review for it upon completion, but suffice to say anyone who enjoys a legitimately unsettling game with a lot of tension needs to play this game. It's well made, it's beautiful, it encourages a lot of replay, and it's far more than a one trick pony. It's a short game, but $10 is hardly a large price to pay for this experience.
The 4th level of the game really really upset me. You're running through a house trying to lock all the windows and doors as the Slender Man watches and draws closer from the outside. Anyone with fears of home invasion will really have trouble with this part.