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 of MicroProse's 1990s X-COM series.XCOM: Enemy Unknown was released on October 9, 2012 in North America and three days later in Europe and Australia for Microsoft Windows, PlayStation 3 and Xbox 360.