You, degenerate president. We'll tell the world about your secret sex life!
~ One of the aliens who communicates between the missions

These unnamed aliens are the antagonists in the Arcade game Space Bomber. They start an invasion on Earth and demand a surrendering. The USA president, however, refuses, and decides to fight the alien invaders by himself using the Space Bomber fighter craft. Once the fight begins, the aliens activate the ruins on Mexico, revealing they have been hiding on Earth for a long time, waiting for the right time to begin their invasion. Between the missions, the president and the aliens exchange threats to each other, but the president successfully defeats the aliens and their king, so they surrender and flee from our planet.

These strange-looking aliens all look like cartoonish balls with small eyes and big lips, often wearing hats and adornments following the thematic of the current stage. They also take on the shape of various cute animal heads and their machinations are just as weird, with giant trash cans and the like.