I like the audio, for the most part. The only problem I see with it is how much gets repeated over the course of one playthrough, including the repetition from Kevin Mcleod's piece which I think is mediocre for a horror theme.
For the rest, I think you should consider context more when trying to build horror, and you really should avoid a time limit for the types of puzzles you used. The first one was basically just click the things in order once you've found the next thing the game arbitrarily allows clicking on. The second one was only different in that the things moved after one of the clicks. The third is certainly a different type of puzzle, which is good since it means your game isn't just repeating the same things over and over, but it was a puzzle so obtuse that even beating it gave me no understanding of how it worked. (I got an iteration with 1, 1, 2, clicked once, and somehow it was solved?). In every case, the reason for the clicks seemed to be purely just what you thought the player character would look at next with no connection to what the character would be afraid of.
Consider this: how would the situation of your game feel for someone who really likes room escapes? My guess is it would be awesome, thus not scary at all.
Further, I think the fact that I had to repeat the action of checking the door knob before I could check the next thing in the first stage killed any chance of horror. The repetition made the in-game actions a routine.