Garry's Mod (commonly abbreviated as GMod) is a sandbox physics game created by Garry Newman and developed by his company, Facepunch Studios. Garry's Mod was originally a mod for Valve Corporation's Half-Life 2, but was later made into a standalone release in 2006 for Microsoft Windows, published by Valve Corporation. Later updates saw an OS X port, added in 2010, and a version for Linux in 2013.
The game being what it is, a sandbox, has been used for a great many things, which are so far are, Sandbox, Scary Maps, Prop Hunt, Hide and Seek, Death Run and Guess Who
This is where Vanoss and others do random things for fun like making sleds to race and going from fighting in wooden mechs to then using a Delorean from Back to the Future. This is also used for making random skits or short stories like a group of friend being toys and having to rescue their friend who is also a toy without being noticed.
This is where the group plays maps intended to be creepy or scary, and most of the time, the maps contain jump scares. The map themselves generally being not that scary, just startlingly because of jumpscares, which is reflected upon titles in Vanoss's video by having "(not really" next to Scary Map.
This is a gamemode where the hunted have to hide from the hunted by disguising themselves as objects within the map that is being played one, and they are given 30 seconds to do so without worry of being hunted. The hunters in videos plus the hunted when not in prop form vary in design based on the model the group chooses to be like their player models, bu usually it's Overwatch Elite model for the hunters, and the scientist player model for the hunted.
To win as props, they will have to wait until time runs out or the hunted health reaches zero, which is usually by the hunted shooting regular objects within the map. The hunted win when all prop are dead
Hide and Seek
Much like Prop Hunt, the hunted are being hunted, and have to prepare themselves in a certain amount of time without worry. But unlike prop hunt, instead of hunters and props, it is hiders and the seekers. Instead of killing, to win is until time run outs or the seeker/s have tagged all hiders. Seekers can not die and hiders who die turn into seekers, and those get tagged get turned into seekers or whatever models Vanoss and others use to differentiate the teams.
This is where the group plays on a map with deadly traps and one has to be the person to activate them while the others must make it through the map. The one who activates the traps is referred as "Death" and that position is decided usually by playing a game at the beginning of the video. The group who go through the map have a certain amount of lives ( which sometimes the group forgets how many they have) and they lose them by dying, and losing all turns them into "Death" If no wins and all lose their lives, then they have to start the map again, but with a different "Death" or give up and do something else to decide a winner" By the of the video, the group usually plays a minigame after the deathrun to decide a "true winner" despite having known who survived at the end.
Like Prop hunt, there are two teams, one is hunting, and the other hides to not be killed. But the difference is they have to blend with NPCs that are spawned throughout the map. The hunted also has powers or special abilities that help them achieve this goal against the hunters like teleportation. Other than that, the mechanics are about the same.