I’d make a reverse slenderman. First person horror, but instead of an enemy that kills you when you look at it, it’s the opposite. YOU kill enemies just by looking at them.
The catch is that there are dozens of monsters and they are all trying to sneak up on you, crawling under beds, hiding behind doors, hanging on the ceiling, etc. And you need to constantly be aware of your surroundings, looking behind you, and checking under every piece of furniture. If they sneak up on you, you’re dead.