Good approach at a nightmare atmosphere. The claustrophobia and feeling of being overwhelmed really come across.
I beat all the enemies, but I couldn't figure out how to win the game. Also, the slow character movement was somewhat frustrating (although it was matched by the slow enemies, so at least it didn't feel unbalanced).
Two small things that you should consider are a bit of animation for the main character and bounding the camera to the playable area.