The last major bastion of human civilization is The City, a coastal city-state located in North America, to the south of an especially toxic region designated the Contaminated Zone.

The City is ruled by the tyrannical Father, who years ago ventured deeper into the Contaminated Zone than anyone had gone before and emerged with advanced weapons technology that he used to seize power.

A handful of Resistance members survive and keep the movement alive under the leadership of Jack's adoptive daughter, Frances Batty Curtis.

The player assumes the role of The Mercenary, an Armored Core mech pilot and former City Police officer who helped quell the First Rebellion and personally encountered Jack Batty during the fighting.

Chief, implied to be an artificial intelligence, returns to confront The Mercenary one last time in a powerful Armored Core named Exusia.

FromSoftware has released a companion application for iOS and Android devices which provides access to a database of in-game parts and weapons to aid in mech customization.

[6] The Daily Telegraph gave the Xbox 360 version four stars out of five and said it was "a brilliant game that is nonetheless difficult to recommend to everyone", but that "those with an eye for detail and a fair amount of patience will be rewarded with a deep, engaging and entirely idiosyncratic experience.

[19] Metro likewise gave it seven out of ten and said it was "still not the game that will make giant robot sims mainstream, but it does have some innovative ideas in terms of both combat and online play".