XCOM Enemy Within CD Key is an expansion pack belonging to the alien invasion strategy turn based tactics war game. This game includes a new gameplay element and has introduced new transhumanism based themes through gene therapy. The developer of the game is Firaxis Game, Feral Interactive, while its publisher is 2K Games. Its producers are Garth DeAngelis and Clint McCaul and designer is Ananda Gupta. The game’s programmer is Justin Boswell and it belongs to the XCOM Series. The engine on which it runs is Unreal Engine 3 and has been designed for platforms like MS Windows, PS 3, OS X, Xbox 360, Android, Steam OS, Linux and iOS. It is both a single player and multiplayer game.
The plot and gameplay is quite similar to that of XCOM: Enemy Unknown, except that it has few additional features. The XCOM headquarters is managed by the player in real time progress, however, most of the gameplay comprises of turn based battles by the humans against the powerful invading aliens, while dealing with EXALT, a rogue human faction. It was released in 2013 and has been stated to be among the best game of that year.