Atomic Heart is an adventure first-person shooter, events of which unfolds in an alternate universe during the high noon of the Soviet Union. The principal character of the game is a special agent P-3, who after an unsuccessful landing on enterprise "3826" is trying to figure out what went wrong.

Set in an alternate version of the 1950s, Atomic Heart takes place in the Soviet Union in which robotics and other technologies have gone rogue. These bioengineering experiments have taken over a manufacturing facility and are running rampant. You play as KGB special age P-3 who is sent to this facility to investigate it after it had fallen silent.