Back in 2004, Garry Newman crafted a specialized "mod" for Half Life 2, and aptly named it, Garry's Mod. The finished product eventually morphed into a Source Engine-based standalone title and made its way to Steam in 2006. Now, 10 years later, Garry's Mod has seen over 3.5 million copies sold and 22 million dollars made. Needless to say, Newman never expected to have any success greater than his sandbox mod, but according to the developer, one of his newest projects is exceeding expectations.

Rust, the kill-or-be-killed standalone title from Newman's Facepunch Studios, has managed to sell 40 percent of what Garry's Mod has to date. Rust hasn't been around for a very long time, and to see such large numbers by comparison, so soon, has really surprised the developer. "We never, ever expected anything to dwarf GMod's success," Newman said. "We can't really believe it." Due to Gmod's widespread prosperity, Facepunch Studios now has 15 employees, and the company is working on a variety of different projects.

Rust pits players against one another with the mindset "simply survive." Gamers have to use their wits and choose who to trust carefully, as the title has no rules to follow. A moral compass is all that keeps other players from killing you and stealing your stuff for themselves. But Rust is more than just a deathmatch of sorts. You'll need to craft items, build fires, avoid wildlife, and make food in order to survive the harsh landscape. According to Newman, it is most likely the game's unpredictability that has made it such a success.