uh, ok if you lack the imagination to come up with a concept for your game...is this really the hobby for you? Secondly, eveyone wants to make horror and it's not hugely original.but anyway, here's an Idea.
It's 1946, the second world war has come to a close.
You are Cole Garland, private in the 107th airborne, undergoing psycological evaluation due to the horrific scenes you witnessed during combat.
The game plays through cole's memories of the war, and the terrible monsters and aboninations he witnessed behind enemy lines.
(Yeah that's a cliche but I had to get the horror angle in there somewhere)
Each level is a different mission that Cole embarked on in the war. With the final level being Cole's attempted escape from his current encarceration in an asylum.
Will he be dead by dawn?
Will he survive the memories of his past?
Will santa ever visit me now im an adult?
Probably.
Now go make the best horror game ever thought up in 3 minutes.
"Guns for show, knives for a pro."