Garry’s Mod is a sandbox mod for the Source Engine. Unlike normal games there aren't any predefined aims or goals. Players are given tools and are left to entertain themselves. The player is in a world where objects can be created and destroyed on demand. Where people can be created and destroyed with the click of a mouse. A world made for him. A world he made.
Waddlesticks says
This is a really great game! WORTH TO GET!
Downside though is that you need the other source games (TF2, Half Life 2, Counter Strike: Source) To get all of the models! But then that is taken off from all the mods you can get!
Great game, gives you hours and hours upon hours and hours of fun! With lan, online or single player.
Worth to get! and nice and cheap!