The ultimate goal is to destroy the Alien Brain , a massive bio-computer that serves as the mastermind and central hub for the invasion. The Endings
Destroying the Alien Brain severs the link between the invaders and their leadership, causing the alien forces on Earth to collapse and saving humanity.
Once X-COM develops the (a powerful interstellar craft), they launch a final mission to Mars.
The modern XCOM: Enemy Unknown reboots this story for a new timeline. In the timeline of XCOM 2 , it is revealed that X-COM actually lost the war early on, and the "victory" from the previous game was a simulation run in the Commander's mind while they were held captive.
Soldiers must fight through the Martian surface and into the underground alien complex.