What is Stop it Slender. "Well, Stop It, Slender. is a really awesome gamemode for Garry's Mod which basically let's you play the orignal Slender game with better graphics and with other players. In Stop It, Slender. one random player gets pointed out to become the Slenderman for a round, and he, or she, will then be given the task of eliminating all the humans before they steal poor Slender's pages. The human's task is to collect all 8 pages, in some maps it might be more than eight pages, to win the round. Who is becoming Slenderman in the next round does not depend on who wins the current round.". Read More about Stop it Slender at.