Really effective! Think the slow pacing through the corridor builds tension nicely.
It did lose quite a lot of its power after the first death, I think following the instructions could have brough with it a couple of scares to keep you on your toes? Was expecting something to be standing behind me whenever I was told to turn around, but it never happened. Think the shader (I assume it's a shader?) effect could be turned down slightly too, the warping of the floorboard texture started to make me feel a bit motion sick.
There's definitely a lot of potential in this though, nicely done