It is the latter part of the 21st century and nanobots (small nano robots) are commonly injected into the human body to deliver chemicals and healing drugs to difficult to reach areas. A new generation of nanobots have been created to take a more active role in human health. These new nanobots can incinerate viruses and bacteria that don't belong. Just as total success was at hand, a new and manufactured plague has risen to challenge the nanobots. These counter-nanobot creatures steal away cells within the body rendering the human incapacitated. Your job is to control the nanobots to fight off these evil agents as long as possible.

The goal of the game is to ensure the cells are kept in a particular partitioned area. If a nanobot is destroyed by an invader, a new one will be injected in after a few seconds. The game ends when all the cells are stolen from the war area.