In year 1999, the ancient prophecy of Nostradamus was fulfilled: humanity was attacked by a terrible disease. It was called Muscular Loosening Disease, or MLD. Before soon, the humans were on the verge of extinction. Under the supervision of the US president, scientists initiated the Human Machiners Project - human body parts were replaced or strengthened by artificial ones, that could resist MLD. But the result was that such humans lost their true nature and became immortal...

Years have passed. In 2039, the futuristic megapolis Zero City is threatened by mutant members of a mysterious organization, who call themselves "Dark Visitor". You, the hero of the game, join the combat unit Debugger, and are assigned to a mission of locating and exterminating the Dark Visitor. Your personal motive is revenge: your family was killed by monsters when you were a child...

Cyber Doll is a futuristic RPG. You fight randomly appearing enemies in turn-based combat, that is viewed from a platform perspective. You have separate hit points for your body parts, and so do your enemies. You have a wide variety of weapons, including small guns that can target one body part of the enemy, and machine guns that cause damage to the entire body. Targeting body parts adds to combat strategy: for example, if the HP of enemy legs is depleted, he won't be able to move and to attack you in close range.