This game is not what you usually see on Steam. In Garry's Mod, you enter a physics sandbox which provides you with tools to make what you want happen and leaves you to it. You can play alone or join thousands of other players kidding around and playing with physics. If you do try this game, do check out its Steam Community Workshop

Garry's Mod or GMod (stylized as garry's mod) is a sandbox physics game using a modified Source engine, created by Garry Newman. Garry's Mod was originally a modification, a "mod", for Valve's Half-Life 2, but was later made into a standalone game. I ...   more on Wikipedia

System Shock 2 Steam Key GLOBAL is a game released on 2000-08-11. Published by Nightdive Studios.

System Shock 2 is a first-person shooter action role-playing survival horror video game for Microsoft Windows, Apple OS X and Linux. The title was designed by Ken Levine and co-developed by Irrational Games and Looking Glass Studios. Originally inten ...   more on Wikipedia

XCOM: Enemy Unknown is an action strategy game developed by Firaxis Games. Play as the commander to a special paramilitary unit called XCOM. Your job is to protect earth from global alien invasion. Manage resources, advance technologies, and plan out individual units as well as global scale strategies to fend off the invading foe! Engage in over 70 unique missions, interact and negotiate with world governments, research alien devices and customize your own instruments of death! Build a base, develop it, grow your own units and participate in turn-based close combat!

XCOM: Enemy Unknown is a turn-based tactical video game, developed by Firaxis Games and published by 2K Games. The game is a "reimagined" remake of the 1994 cult classic strategy game UFO: Enemy Unknown (also known as X-COM: UFO Defense) and a reboot ...   more on Wikipedia

Empire: Total War is a massive strategy game that drops you into the 18th century and puts you at the wheel of an empire. You will have to dominate your opponents both in the seas and on land, all to make sure that your empire is the one to come out on top in this tumultuous time referred to as the Age of Enlightenment.

Empire: Total War is a turn-based strategy and real-time tactics computer game developed by The Creative Assembly and published by Sega. The fifth installment in the Total War series, the game was released in North America on 3 March 2009, and in the ...   more on Wikipedia