In this 1973 kaiju film, the peaceful undersea nation of Seatopia unleashes the giant monster Megalon to wreak havoc on the surface world as retribution for nuclear testing. Meanwhile, a scientist, his young brother, and their friend find themselves caught in the chaos and must summon the help of Godzilla and the robot Jet Jaguar to combat the threat. Directed by Jun Fukuda, the film is known for its campy special effects and action-packed sequences. Although it did not receive any major awards, it remains a cult favorite among fans of the genre. For those interested, the movie can be viewed for free on 123Movies / Movies123.