Was with you right up to the end
You're one of the very best on Newgrounds at building tension and evoking real, visceral emotion in your work, and here you did so to excellent effect. This was among the best of your work in creating a disturbing atmosphere through dissonance. Also, your limited palette design and perfectly balanced sound work were exceptional. This was real Stephen King material.
What a letdown that you should undermine it with such a cheapjack ending. Even when King cops out for an ending, it's at least a giant spider -- this is so far beneath the buildup that even "there, on the door, was a HOOK" would have been better. This ending looks like you picked it by poll on 4chan.
The first 9/10ths is great, but the ending turns it all into LOL JOKE HERE. Why watch it twice?