Love the atmosphere and the sound work.
I feel like the creatures don't give enough time to react, given the slower speeds of the characters.
Something else that I've not been able to see is if you can complete the game without a survivor. With the number of doors I've run into, I don't know if it's possible. Maybe make sure that the game can be completed with no doors (the doors make it easier, but not necessary) or fail the game when even one of the survivors dies.
I'm not sure if there is/was plans for something for the weapons, but right now they are misleading in the game as they seem to do nothing. Maybe you could replace them with abilities specific to the survivor?