I am quite unable to play horror games so that knock, knock... shivers!
I like the general low res style, as it gives an aesthetic that is able to hide the short time we had to develop while preserving certain identity. I think that giving less information, visually, also feeds the feeling for The Unknown to be out there, looking for us.
Including submechanics such as the Simon Says adds layers of interaction, which is always good if you strive for immersion; it makes the player feel that this world is alive, that is has its inner logic.
Pushing t he player to turn the light was also a great detail, same as letting the window and the TV at his back when doing so. It is all about pushing against what makes you feel safe. Good combination.
I also liked how you bravely used posters to point out what to do. It is as if the game wasn't trying to hide it is a game, stating that this is about getting scared on purpose.