XCOM was a planned first-person tactical action sci-fi game and a reboot of the classic tactical strategy X-Com series originally developed by Mythos Games and MicroProse, while focusing on a new origin story. Developed by 2K Marin, it was originally announced for a release on March 6th 2012 but was pushed back to a release between April 2013 - March 2014. On April 15th 2013 the game's websites were shut down and on April 26th 2013 it was re-announced and retitled as The Bureau: XCOM Declassified, a tactical third-person shooter that released August 20th 2013.
Featuring a bold new origin story told from a first-person perspective, XCOM pits Special Agent William Carter and his veteran team against the threat of human extinction. But every enemy is an opportunity - players will strike surgically against the alien menace, capture their technology, and by the science of desperation - turn the invaders' weapons against them. Armed with these lethal new tools of war, players will command their squad on XCOM's front lines: Main Street, USA. 
E3 2011 Trailer