Scary United Co-op

Scary United Co-op is a multiplayer server on Garry's Mod created on May 27, 2013.

The first map comprises a locked corridor with a crate emitting strange sounds, followed by an encounter with fleeting zombies that reappear upon the player's death. Upon opening a door, a closet emits eerie noises from Far Away Ambient, leading to a room with two doors. The left door releases a zombie, while the right door spawns two radioactive zombies. The next yellow room features a blood-soaked bathroom and a corpse, accompanied by a loud scream.

In the second map, the player enters a room with two people on a couch who vanish suddenly, leaving a bloodstain. The next room has an NPC Zombie that chases the player while producing a deafening scream. In the classroom, the player encounters a 4 pyramid symbol on the chalkboard and Gman from the Half Life series standing beside it, who disappears when approached, with the chairs moving momentarily. The player must locate the "4 Pyramid Symbol" to unlock the subsequent puzzle part. Upon completing the long corridor, a box appears, bearing the warning message "IT'S A TRAP" leading to a blood trail that guides the player to a door that unleashes a jump scare. The player must walk down the stairs and avoid a close-up action of a zombie that kills the player.

In the last part, two players must press three options to open the door, leading to the end screen with a message reading "But it's a trap!" If the player continues, a picture of a face from "What's Wrong?" pops up, followed by a loud scream. The player can then proceed to the end screen.

Links
NOTE : The following game contains a screamer!
 * steamcommunity.com/sharedfiles/filedetails/?id=148332613
 * Gameplay commentary: youtube.com/watch?v=t8ZOAHoy2PQ