The world has fallen in to total chaos because of the Cybercon III computer system. Designed to coordinate the defense systems of many nations, the autonomous computer has unleashed nuclear warheads and robotic weaponry against all of humanity. Extinction is not far away as the last remaining pockets of human resistance are remorselessly fought by the machines.
However, a chance discovery has revealed the location of Cybercon's central Brain Stem, and with it a hidden back door into the defense complex which protects it. Donning a powered maintenance exoskeleton, you must penetrate the complex, destroy or avoid the robotic guardians, and discover the hidden key codes which allow access to the Brain Stem.
Cybercon III is presented as a first-person full 3D polygonal environment, albeit a flat-shaded (untextured) one, and was one of the earliest games to feature such. The player has freedom to explore the whole complex, must navigate through many rooms, across narrow ledges and deep canyons, and through disorientating mazes.
The ultimate aim of the game is to locate the sonic key codes that unlock access to the central Brain Stem of Cybercon, and then destroy it. The player starts with a set of sonic keys (presented as color/shape combinations) which allow access to various piece of equipment (for example doors, elevators and retractable bridges) throughout the complex. New key codes can be found and allow access to more equipment and new regions.
A major game system is the player's powered armor, which has a number of primary and secondary systems which may be independently enabled and disabled. Up to four energy banks provide power, some of which may be self-charging fusion batteries. The level of available power and the number of enabled systems affect the performance of the systems, so for instance the player may choose to jump higher via the power-assisted movement system by disabling the weapons and shields, or fire more powerful shots by disabling all but the weapon system. Other systems include the sonic key, self-repair, and energy transfer systems.
Roaming the complex are a number of (polygonally rendered) robots, including tanks, giant wheels, and "angel droids", some of which can be much larger than the player. Damaging the robots without fully destroying them can cause them to drop useful items, such as extra energy batteries, power storage spheres, and other upgrades. Other items which can be found in the complex include a bazooka weapon, and cameras that can be placed and remotely viewed on the HUD, including the remotely pilotable "parrotcam" which is useful for scouting areas safely.