Nice. The atmosphere and feeling of dread work great in tandem with the art. The difficulty felt fair to me as well (considering 2D platformers are often challenging for me).
There were some parts of the music which felt a little happy given the environment, but that could be considered creepy as well.
I wonder if you could keep your powerups upon death? I got the double jump, died, I realised that I'd have to go back and grab it again. Maybe there's a mid ground?
Overall, great job!