Garrys Mod is a sandbox game that is based upon the idea of building .It is a game with no set rules and no set objectives. This means that you can neither win nor lose in this physics based game. Despite these limitations, Garrys Mod has become very popular among the gamers around the world. Not many people know that Garrys Mod was not created as a game but just as a mod for another game Half Life 2. The game has however sold more than 3 million copies and earned more than 20 million dollars. You can download Garrys Mod non steam here for free.