Here is my lets play.
The atmosphere was definately something else I will say. The fact you were very slow when walking, along with the liminal space-esque feel added to the creepiness factor. That, and the limited control of the character, when in some cases you wanted to turn round but couldn't really elevated the impeding sense of dread as the game goes on.
Even when I know it didnt work, I kept seeing myself instinctively mashing the shift key as if it would do anything, only to when it did, did my panic set in. It was creepy, and despite me having second thoughts on wanting to play it, it was actually fun in hindsight.