This Source-based mod takes a different approach by creating a sandbox environment instead of offering custom content. This enables the player--or in this case the designer--to experiment with a special physics gun that can manipulate props created by the community and those already found in a Source-based game (Half-Life 2, Counter-Strike: Source, etc.). By using the physics gun, players pick up objects from any distance, adjust their position, and freeze them in place. The accompanying gun can then weld the manipulated props together, connect them by using ropes, or combine them using other functions to ultimately create a working contraption.
"The simplest example is a car," explains the mod's description. "The player spawns an object to be used for the car's body then adds wheels by firing the tool gun at the object. Wheels are then controllable using the number pad on your keyboard. You don't have to make moving contraptions, though--want to build a fort out of wooden crates then set it on fire? Go for it! Want to build a house using fridges for the walls and mattresses for the ceiling then drive a jeep into it all? Go for it!"
In addition to the tools, Garry's Mod lets users manipulate characters' facial expressions and move their eyes. With that said, inventive artists could theoretically create a comic book. Garry's Mod also provides the means to create unique game modes such as Melon Racing, Go Fish, and more.