The first part of the game is a first-person shooter in which you control the pilot and the exoskeleton "Titan". The player has the ability to move around the battlefield by jumping and running. The player can also shoot the enemy by using a variety of weapons, including guns, grenade launchers, missile launchers, and rocket launchers. You can also use the abilities of the pilot and the Titan to perform various tricks, such as flying over the enemy, jumping on the enemy, and destroying the enemy.

The main plot of the game is the confrontation of the people's Militia with the IMC Corporation, which seeks to destroy the rebels of the Frontiers, a region of star systems. The rebels of the Frontiers have formed a group called the Frontiers Army, which is fighting against the IMC Corporation. The player plays as Jack Cooper, a soldier who dreams of becoming an elite pilot with advanced technology and a personal Titan, a fighting machine. The player can use the Titan to fight against the enemies of the Frontiers.