A heavy condensation of the original serial compresses the original thirteen episodes into an efficient 97 minute feature. Disaster seems imminent when scientists discover that the planet Mongo is about to crash into Earth. Luckily, heroic young Flash Gordon is on hand to lead an investigative mission into outer space and onto the speedily approaching planet. There, he and his best girl, Dale, who is along for the ride, learn that Ming, the devious ruler of Mongo, has purposely put the planet on a collision course with Earth, and only Flash can stop him.
In the near future, big wars are avoided by giving individuals with violent tendencies a chance to kill in the Big Hunt. The Hunt is the most popular form of entertainment in the world and also attracts participants who are looking for fame and fortune. It includes ten rounds for each competitor, five as the hunter and five as the victim.
A nuclear explosion in the far north unleashes Gamera, the legendary flying turtle, from his sleep under the ice. In his search for energy, Gamera wreaks havoc over the entire world, and it's up to the scientists, assisted by a young boy with a strange sympathic link to the monster, to put a stop to Gamera's rampage.
When an atomic war on Mars destroys the planet's women, it's up to Martian Princess Marcuzan and her right-hand man Dr. Nadir to travel to earth and kidnap women for new breeding stock. Landing in Puerto Rico, they shoot down a NASA space capsule manned by an android. With his electronic brain damaged, the android terrorizes the island while the Martians raid beaches and pool parties
After landing on a mysterious planet, a team of astronauts begin to turn on each other, swayed by the uncertain influence of the planet and its strange inhabitants.
In 2020, after the colonization of the moon, the spaceships Vega, Sirius and Capella are launched from Lunar Station 7. They are to explore Venus under the command of Professor Hartman, but an asteroid collides and explodes Capella. The leader ship Vega stays orbiting and sends the astronauts Kern and Sherman with the robot John to the surface of Venus, but they have problems with communication with Dr. Marsha Evans in Vega. The Sirius lands in Venus and Commander Brendan Lockhart, Andre Ferneau and Hans Walter explore the planet and are attacked by prehistoric animals. They use a vehicle to seek Kern and Sherman while collecting samples from the planet. Meanwhile John helps the two cosmonauts to survive in the hostile land.
Dr. Steven Sorenson plans to tap the geothermal energy of the Earth's interior by means of a thermonuclear device detonated deep within the Earth. This experiment causes a crack to form and grow within the Earth's crust, which threatens to split the earth in two if it is not stopped in time.
The superhero Starman is sent by the Emerald Planet to protect Earth from belligerent aliens from the Sapphire Galaxy. The Sapphireans (or "Spherions") kidnap Dr. Yamanaka and force him to use his spaceship against the Earth.
A scientist experimenting with suspended animation decides to use himself as a test subject. Before he is frozen, his wife is killed, and he is suspected of her murder. a murder suspect.
Martians fear their children have become lazy and joyless due to their newfound obsession with Earth TV shows. After ancient Martian leader Chochem suggests that the children of Mars need more fun—including their own Santa Claus—supreme leader Lord Kimar assembles an expedition to Earth. Once there, they kidnap two children who lead them to the North Pole, then capture the real Santa Claus, taking all three back to Mars in an attempt to bring the Martian children happiness.
Radioactive waste dumped off the coastline creates mutant monsters. The beasts attack slumber parties, beaches, tourists, and terrorize a waterfront community as a scientist, his daughter, her boyfriend and the local police try to find a way to stop them.
An alcoholic actress, her personal assistant, and their pilot are downed on a secluded isle by bad weather, where a renegade Nazi scientist is using ocean life to develop a solvent for human flesh. The tiny flesh-eating sea critters that result certainly give our heroes a run for their money - and lives.
The legendary empire of the lost continent of Mu reappears to threaten the world with domination. While countries unite to resist, an isolated World War II Captain has created the greatest warship ever seen, and possibly the surface world's only defense.
After an astronaut space capsule is detonated in orbit, with the astronaut begging to be killed, a teenager couple finds a severed arm on a remote beach. The boy takes the arm home, where it becomes animate and the alien force which animates it soon possesses his mind as well.