Let us never underestimate the internet's ability to come up with freaky crap. The vast reach of the web creates mysteries as often as it dispels them, and sometimes those mysteries are truly scary.
The "Slenderman" is a longstanding horror meme based on the mythological archetype of a tall, faceless man who appears in the dark and… does scary things. Steals you away, grabs children. That kind of thing. He's haunted lots of places, from message boards to Minecraft, and feels a bit reminiscent of that freakshow in Pan's Labyrinth or even Jack from The Nightmare Before Christmas.
YouTuber AgentParsec has crafted Slender, a simple Unity-based horror game that stars the Slenderman. It's very simple, and free to download (links are below). In it, you'll play as a nameless woman (going by the sounds of your breath when you run) who must go around a closed in park at night and collect eight notes. You've got a flashlight, and that's about it.
And yet the game is super freaky. It's amazing just how simple horror can be—put me in the woods at night with a flashlight and no means of defending myself, set a scary monster after me and… well, I'm gonna be scared. Bonus scary points for putting vague fun-facts about the monster on the notes.
There seems to be a bunch of great indie horror games out at the moment, huh? Fine by me.