Flash Gordon: The Greatest Adventure of All

In the late '70s, producer Lou Scheimer acquired the rights to produce a live-action Flash Gordon movie-of-the-week for NBC, and he commissioned Samuel A. Peeples to write the script. Peeples' script was deemed unfilmable in live-action, so it was decided to shoot it as an animated film. NBC wouldn't give Scheimer additional funds for animation, so he turned to Dino De Laurentiis, who agreed to give him money to complete the movie in return for helping him to secure the rights to make the theatrical film Flash Gordon (1980). NBC was so wowed by the animated film that they decided to shelve it, recut it and run it as the Saturday morning series Flash Gordon (1979). After the series ended its run, the original film was finally aired during prime-time in its entirety.

The fluid movements of the human characters were achieved by filming extensive live-action footage of human actors for rotoscoping. Filmation's effects department built models of the spaceships for the same purpose, painting them white and covering them in thin black lines. Using a computerized camera, the film negatives were printed as cels, creating "positive" versions of the ships for the animators to use in rotoscoping.

Ted Cassidy's last project.

While the film has considerable fidelity to the original comic strip by Alex Raymond, there is a change to ensure that Dr. Hans Zarkov is a sympathetic character in the film. Namely, while in the comic strip, Zarkov forces Flash and Dale into his rocket ship at gunpoint, the film has Zarkov rescue Flash and Dale from certain death from falling with a burned parachute from a meteor shower attack on Earth by Ming the Merciless and then leads them to his hidden laboratory even as they are threatened by a pursuing flood of molten lava. Once there, Zarkov invites the pair into his rocket as the lava floods his lab, which makes boarding it the only chance of survival they have. After the trio escape in the rocket, Zarkov apologizes that he cannot drop them off before continuing to Mongo and then explains what he intends to do there to save planet Earth. For their part, Flash and Dale are satisfied by that explanation and agree to help Zarkov.

It was shown in the UK on ITV on 22 December 1983 at 10:25am.