X Multiply (1989)

Is a side-scrolling shooter published by Irem, and similar in style to their earlier R-Type. The game centers around an unusual alien invasion against a colony planet in the year 2249 where the aliens themselves are microscopic creatures that invade, infect, and kill the colonists. Scientists have deployed the microscopic fighter X-002 into the body of the hapless woman whose body has been invaded by the alien queen.