Im working on a survival horror game called St Abraham, set in the St Abraham Mental Institution. Your character, Jay Donovan, is a man who killed his family because ghostly voices told him to do it in his sleep. The hospital becomes overrun with demons and monsters after he is admitted, due to the architect who designed the hospital being a cult leader who used a pentagram-like symbol used for rituals as the hospital's logo.
The main gameplay mechanic is hallucinations. You will sometimes see monsters that aren't actually there. They will attempt to attack you, but they can't deal damage. You will also see ghosts and very other things to mess with your mind. You will also hear voices telling you to do certain things. Sometimes the thing the voices are telling you to do is something you must do to continue, but sometimes it's a trap that can lead you into a monster. So its a game about never knowing what the consequences of your actions are going to be.
There is also sort of a lack of combat. You can defend yourself, but you only wield a small handgun with limited ammo and a wooden board as a melee weapon that breaks after taking enough damage. Ammo and health are scarce, making players ration supplies.
Does anyone have any suggestions or ideas, mostly for scares? Any things that could be changed?
EDIT-----------------------------12-27-12
There are five "hubs", each seperated by a boss. Now, I know most of you are thinking that boss battles diminish the horror, but these don't. Even during the bosses, you feel helpless. For example, the first boss is a large lizard-shaped thing with a line of anglerfish-like lights running down its side. The lights of the arena occasionally turn off, meaning you can only see the boss from its own body lights until the lights turn on again. Other bosses include an angry invisible monster in the sewers and a giant blob of human flesh.