The object of the game is to cool down the core of a nuclear reactor without being pushed into its walls by swarms of subatomic particles.
Reactor was developed by Tim Skelly, who previously designed and programmed a series of vector graphics arcade games for Cinematronics, including Rip Off.
[2] Reactor was ported to the Atari 2600 by Charlie Heath and published by Parker Brothers the same year as the original.
The player starts the game with a limited number of decoys, which can be deployed by pressing the Decoy button in order to lure particles toward the kill wall, control rods, or either of two small "bonus chambers" at opposite corners of the screen.
In later levels, the core is replaced by a slowly expanding vortex that can attract the player's ship and destroy it on contact.
"[4] A 1983 reviewer for Hi-Res magazine wrote, "VCS Reactor's main flaw is not in the game itself, but the flexibility of the controlling joystick.