October is the one time where I feel compelled to play horror games in order to be a good festive citizen. They both fascinate and terrify me. Cameron Kunzelman, in his "designing horror" series, examined why the game Deep Sleep is disturbing.
The aesthetic is a dream aesthetic. Things change before your eyes. Objects that have no business interacting with one another do, in fact, work together (a net and a hook?). There is no reason for being in a place and doing a thing except for the fact that it is the thing to do at the time (dreams work a lot like games, come to think of it). So Deep Sleep gets to have its creepy aesthetic and strange aural landscape be as weird as it needs to be because we all implicitly understand that dreams are just like that.
On one hand, it feels a little lazy. Of course an inherently unstable state creates unstable aesthetics, which neatly elides into horror (this is why David Lynch can be so goddamn scary sometimes.) On the other hand, that is exactly the point, so I have to commend the designers. It is a dream gone bad; literally a nightmare machine that produces itself in front of you.
That, in essence, is how Deep Sleep works. It makes you believe that everything is going to be okay. It is a liar.
Making a nonsense world can be terrifying, if it's done right.