I just saw this little horror game gem called "Hide". It is a very simple game with very simple graphics. Basically the game is all about finding five signs scattered across a map while avoiding being found. I think it is a great example in how not showing something properly makes the imagination go wild. The extremely sparse (yet workable) graphics and the atmospheric soundscape forces you to immerse your self and imagine your worse fear.
The game only takes a few minutes to play, so I suggest you all give it a go. And do not forget those headphones!