Bart vs. The Space Mutants is a platform game where the player goes into the role of Bart Simpson (from the TV show The Simpsons) and must stop the Space Mutants from invading Springfield. On each of the five levels, Bart must collect (or get rid of) the ingredients that the Space Mutants are planning to use to build their machine, such as purple objects or balloons. He also has to collect enough "proof" of the aliens existence (brown coins left behind when they are jumped on), so his family members will help him when he meets a boss (characters such as Nelson and Sideshow Bob). This won't be easy since the Space Mutants are "using" human bodies as disguise. In order to discover who are the real Space Mutants, Bart must use his X-ray Specs.
