I liked the game, and to be honest when i first saw the TV slenderman, when going up the stairs to get the tape from "my room" it really got the chills on me.
That being said.... it felt like the end fell a bit short of expectations. It felt rushed and unpolished. The monster knocking on the front door made no sense since it was already in the house.
But on a side note, i really liked the graphics of the game! The controls were a bit awkward, the camera sensitivity being a bit too high for me, at least on Linux and with my configuration
Overall, I'd say it's a 7.3/10. It's a good game, but it clearly lacks some things