Conquer your fear and gather all 5 trading cards! Each card adds a little lore to the crazies backstory and collecting them all can result in some pretty spooky backgrounds for your steam account.
Good Luck!
-Note: There is a small glitch with the level number shown on the title screen once you've beaten night 11. Don't worry, it is accurately remembering your level despite the display being off just a tad.