XCOM Enemy Unknown is a reimagining of the classic 1993 strategy game where players control XCOM, a secret paramilitary organization tasked with defending Earth from an alien invasion. As commander, players will build and manage an operations base, research alien technologies, plan combat missions, and control soldiers in turn-based tactical battles against aliens around the world. Key features include leading a global defense against the alien threat, developing a strategic base of operations, and engaging in multiplayer tactical combat.