By 1964 the Xmen have been formed by Charles Xavier and Erik Lehnsherr, alongside Raven Darkholme, Sean Cassidy and the other mutants who originally rose up to oppose Shaw, after failing to stop nuclear war. They are branded terrorists in a society they seek to save.

Sebastian Shaw is seen as a figure head for a new and better world, posing as the President of the United States of America while he has formed a resistance task force to sweep aside any who oppose him.

Which side will you choose?

Atom is set in 1964, in a post apocalypse setting following real time. The game is canon compliant up until the point where the X Men stopped the Soviets from crossing into Cuba's waters.