(The black at the ends of the halls is the void as this is just a hallway segment.
Does anyone know what I can add/change to make it more like the picture or just make it more eerie overall?
Constructive criticism is encouraged, I want to know what I can change, and feel free to tell me if the build is flat out awful, I want to know how I can improve it
Well, as @sonic_848 suggested, turn down the lighting. You can also have a script on some of those painting to switch the background to a horrific scene and then switch back quickly, like a jump scare…or have eyes that follow the player.
That painting with the side of a face…you could switch it to something that shows it without it’s skin and switch back quickly. You could also have a faint apparition patrol the hallway at random times. To really freak someone out, you could sweep a light across the backside of the door. It will make it look like someone is in a room with a flashlight, but if they go in the room, nobody is there. Then there’s the usual flying green orbs. If you do that, make them faint, translucent, and glowing.
For a horror game, you want to convey the sense of something evil lurking in the house which should invoke a feeling a fear, or dread.
A hallway is a hallway. You can try to dim the lights. You can also use filtering to limit the visual range. Take a look at a game called doors. They have a pretty good example of a horror setting.
Another game is survive the killer. It’s been awhile since I played it, but they have a haunted house map.