You take on the role of Dr. Smallship, a doctor in the late 21st century that invents a powerful shrinking device. With a new deadly bacterial infection spreading across the world that medical science has no cure for, our doctor gets the idea of shrinking a fully-armed space fighter in order to do things the old-fashioned way! The governments of the world quickly step in to offer their assistance, and five combat ships specially designed for inner-body combat are prepared for the dangerous mission of cleansing the body of the first test subject -- er, patient -- to undergo this dangerous surgery.

This is of course his first attempt at such a mission, so hopefully things all go to plan. If they do, the world may have hope yet!

Unfortunately, on your way into your patient, you were ambushed by several foes who managed to consume all of your weapons except your primitive energy weapon, the Blaster! Hopefully as you work your way through the patient's body, you'll recover them. Especially that experimental Freeze Bomb...

The objective of the game is to pilot your ship, through the body of your first (brave!) patient who is infected with this deadly nameless bacteria, and destroy the sinister bacteria that are eating away at the patient's innards. You will visit the brain, the stomach, and finally the heart of the patient; the three areas that the bacteria attack. There is evidence that suggests a massive 'boss' bacteria that commands all of the others with its enlarged nucleus. Let's hope he didn't manage to consume any of your weapons!