Not half bad, only why play this, if you can just download the real thing? Of course I appreciate the effort put in this, even though it's not as scary as the real thing. You can easily get away from Slendy by just running past him, he has crap AI. This game is easy as it is, adding flashlight toggling, which there is in the real game, would make this possible to accomplish with next to no effort.
But I won't be a total jerk, I have to say it's the closest thing to Slender on the internet. Appreciate the work, even though more could have been put into it. 3,5 for the effort.