Well, I have to make a 2D game since idk how to make a 3D game and I didn't have enough time to learn how to. And this is also my first time making a horror game.
I think making something feel lifeless while having good ambience and tension build-up could really make a scary 2D horror game. Think Andy's Apple Farm, which doesn't rely on jumpscares. Maybe give the player a restricted view? Like adding a more darker filter to the camera and vignette?