Godzilla vs. Megalon

Nuclear testing unleashes mayhem on the undersea kingdom of Seatopia, causing a series of environmental disasters. To exact revenge, Seatopia unleashes Megalon, a gigantic beetle with the ability to fire ray beams and napalm bombs. Meanwhile, a schoolboy creates Jet Jaguar, a flying robot with a built-in moral compass. The inevitable matchup of Godzilla and Jet Jaguar versus Megalon and Gigan decides the world’s fate.

In Japanese with English subtitles.