XCOM: Enemy Within is the standalone expansion to the 2012 Strategy Game of the Year and includes the base game experience with all new expanded content as well as the Elite Soldier Pack, Slingshot and Second Wave add-on content. Enemy Within adds an incredible array of new abilities, upgrades and weapons to combat new enemy and alien threats. This expansion pack also introduces new maps, new tactical and strategic gameplay, and new multiplayer content providing a fresh new gameplay experience.

Great game, need to find another 1 with the same style of game play.