I've played Slender, it's one of the stupidest games I've ever played.
You walk around a PS2 or below pixelated forest trying to find 6 pieces of paper while an equally horrible pixelated guy in a business suit with laughably stupid long arms... walks behind you from time to time.
Either people are over exaggerating the scare factor (they are, it's how they get more views on their channel/videos), or this generation is pathetically weak when it comes to anything horror related, if you can even call this "game" that.
"You lack the requisite spine and testicular fortitude to study under me"
"You do not know the first note of the music that moves me."