In the year 2041, the rebel Centros are a plague to the survivors of the great toxic gas scare of 1993. A renegade Megarobot pilot and an archaeologist must team up (despite personal differences, a reluctant romance, and official pressure to cease and desist) to thwart the Centro's attempts to resurrect a hidden Megarobot, with which they can challenge the prevailing order.

Ever since the world was born, two forces have been locked in perpetual battle. Their struggle is so Manichean, so ferocious, so Herculean that it makes the clash between good and evil look like a game of checkers! This ancestral duel is so ancient and so merciless that it can only be, Oggy against the Cockroaches!