What makes a good horror game for me is to scare without drawing attention to the scare. Have a face watching you through the window that disappears once your camera is centred on it long enough. Can even have some disturbing scurrying sounds accompanying it. If there’s a ghost, have it appear in front of you for several frames and vanish. The idea being it’s only in front of you long enough to notice it but never long enough to get a good look at it. Silence too. Really harsh music can sometimes take away from the horror. You have something to focus on that isn’t the scares. Silence let’s the atmosphere brood and any sound feels amplified. Other scares can be the sound of things being knocked over like somebody is clumsily walking in the dark.

Tl;dr what makes a scary for me is creating this atmosphere that you are not alone and whatever is watching is constantly in the room with you at all times.

What about you? When playing a good horror game, what was it about the horror that stood out to you as a good attempt at horror?