In the game you control the space ship of Space Bug and try to prevent objects from colliding to Earth. These include missiles, asteroids, comets etc... The pace of the game raises in each of the 20 levels. The objective is to survive and to save Earth from this battle.
Though saving the day is nice, it's even nicer to save the day with more points than your friend! You could say that the primary objective of Space Bug is to make the number 1 high score!