Godzilla vs Megalon (1972) Review | Godzilla Island Archive

The Plot

The movie opens with nuclear testing in the ocean. On Monster Island, Godzilla and Anguirus are caught in clouds of radiation and pollution caused by the blasts. Meanwhile, deep beneath the waves, the people of Seatopia are furious — the tests are destroying their underwater civilization. Determined to strike back against the surface world, they declare war on humanity and vow to reclaim the Earth for themselves.

On the surface, inventor Goro is spending the day with his nephew Rokuro and his friend Hiroshi. Rokuro rides around on a fish-shaped boat of Goro’s design when suddenly the lake begins to churn violently. An earthquake hits, and the trio rushes to safety as the Seatopians drain the entire lake — a sign that something sinister is coming.

When they return home, Goro, Rokuro, and Hiroshi discover their house has been broken into. They’re ambushed by Seatopian agents and knocked unconscious. Strangely, nothing appears to have been stolen. Goro then shows Hiroshi his latest creation — Jet Jaguar — a humanoid robot he designed to follow his commands. Jet Jaguar isn’t fully completed yet, but that’s about to change.

While Goro and Hiroshi continue their work, Rokuro rides his mini-bike outside and is kidnapped by the same Seatopians who broke into their home. They use him to trick Goro into opening the door, then capture both Goro and Rokuro, leaving Hiroshi tied up inside. The Seatopians plan to use Jet Jaguar to guide their monster, Megalon, as he attacks the surface world.

Goro and Rokuro are sealed inside a shipping container while Hiroshi struggles to break free. Once he escapes, he tracks down the container and rescues them. Goro reveals he’s built a secondary voice controller that can override the Seatopians’ commands. Using it, he stops Jet Jaguar just in time to prevent a helicopter collision and then orders the robot to find Godzilla and bring him to help.

Jet Jaguar flies to Monster Island to recruit Godzilla, while Megalon rampages across Japan. Realizing their plan is in jeopardy, the Seatopians call upon their allies, the Nebula M aliens, to send Gigan to assist Megalon.

Jet Jaguar returns, now mysteriously able to grow to Godzilla’s size. Goro speculates that Jet Jaguar must have reprogrammed himself — adapting to survive in any situation. He bravely battles Megalon one-on-one until Gigan arrives, and the odds turn against him. Fortunately, Godzilla soon appears, leading to an epic tag-team battle: Godzilla and Jet Jaguar versus Gigan and Megalon.

After a long, destructive fight, Godzilla and Jet Jaguar emerge victorious. Gigan retreats back to space, and Megalon flees underground to Seatopia. Godzilla and Jet Jaguar celebrate their victory with the most famous handshake in kaiju history before parting ways. Godzilla returns to Monster Island, and Jet Jaguar shrinks back to human size, reuniting with a relieved Goro, Rokuro, and Hiroshi.

My Thoughts

While Godzilla vs. Megalon is undeniably corny at times — especially when the “Jet Jaguar theme song” kicks in — it’s still an entertaining ride for any Godzilla fan. This film often gets labeled one of the weaker entries in the series, but as a lifelong fan, I can’t help but enjoy it.

One thing that always bugs me, though, is the Seatopian's logic. If they’re ancient humans who once lived on the surface, why not just return peacefully and explain their situation? Instead of sending a giant beetle monster to destroy Japan, they could’ve said, “Hey, your nuclear tests are wrecking our city,” and humanity might’ve stopped. But then again — without the misunderstanding, we wouldn’t have this gloriously cheesy movie!

An interesting bit of trivia: Godzilla vs. Megalon wasn’t originally meant to be a Godzilla movie at all. It started as a children’s film titled Jet Jaguar vs. Megalon. The Godzilla elements were added later after Toho decided to rework the project. Jet Jaguar himself was created through a children’s design contest — the winning drawing inspired the robot we see in the film and has since grown to develop a cult following of fans in the Kaiju fandom.

It’s funny to think that this was supposed to be a kid’s movie, considering it includes a child kidnapping subplot and, in the original Japanese version, even pin-up posters in the background of a truck scene (these were removed from the U.S. release to secure a G-rating). I never noticed that detail watching the VHS as a kid, but it definitely caught my eye on the newer uncut DVD.

I first watched this movie as a child, and despite its flaws, it still gives me that nostalgic rush. It’s colorful, campy, and full of that classic 1970s kaiju charm. If you’re new to the Godzilla series, this one is worth checking out — especially if you love weird side characters like Jet Jaguar.

Until next time — enjoy the corny Jet Jaguar theme song, and remember: sometimes the cheesiest Godzilla movies are the most fun.