The game's development was protracted and troubled. Players can permanently lose their squad members so they must make good tactical decisions. As a tactical shooter, players can use the battle focus mode to issue commands to two other agents accompanying the protagonist, William Carter. Set in late 1962 at the height of the Cold War, the game's premise mainly revolves around The Bureau, the predecessor of the Extraterrestrial Combat Unit (XCOM), as they attempt to repel an alien invasion. As the eighth title in the turn-based strategy series X-COM and a narrative prequel to XCOM: Enemy Unknown, the game was released for Microsoft Windows, PlayStation 3 and Xbox 360 in August 2013. It was developed by 2K Marin and published by 2K Games. The Bureau: XCOM Declassified is a 2013 tactical third-person shooter video game.