I don't remember the Flash Gordon cartoon
Filmation's
Flash Gordon started in 1979 as a TV movie that was much more lushly animated and rather more adult than their usual stuff -- Flash and Dale meet during a WWII battle in Europe, Ming is allied with Hitler, there's lethal violence, the heroes' clothes are ripped alluringly, etc. -- and was also remarkably faithful to the original comic strips. But unfortunately, legal conflicts with Dino DeLaurentiis's 1980 live-action
Flash Gordon movie (I think) prevented the far superior Filmation movie from getting released until a single, never-repeated showing on prime-time TV in 1982, and it's never been released on home video in the US, though a version ripped from a Japanese DVD release
is on YouTube.
Anyway, the first season of the TV series (which is on home video) is basically a reworked and expanded version of the movie, starting
in medias res after the WWII stuff and redrawing Flash, Dale, and Zarkov in their later Mongo costumes throughout so that it would be easier to reuse animation and intermix movie scenes with TV scenes, since the plot was stretched out with a lot of episodic side adventures between the main plot points of the movie, so that it plays out much like the Flash Gordon movie serials of the 1930s. Surprisingly, they kept Aura's really skimpy bikini-like outfit rather than redrawing her in something more modest. Anyway, because it incorporates so much footage and reused/retraced animation sequences from the movie, it's far more richly animated than most of Filmation's shows. It recasts most of the voices from the movie aside from Flash (Robert Ridgely), Dale (Diane Pershing), and Aura (Melendy Britt), so that it could have a smaller ensemble; Alan Oppenheimer (as Zarkov and Ming), Allan Melvin (as Thun and Vultan), and Lou Scheimer (as the announcer and bit parts) rounded out the TV cast, with Oppenheimer using the exact same voice for Ming that he'd later use for Skeletor.
Unfortunately, for the second season, NBC insisted on dumbing it down more and playing up comedy at the expense of adventure, dropping the serialized format and doing two half-length episodes per show, as well as adding "Gremlin the Dragon" as a comedy sidekick who dominated the show. It was a shadow of its former self, let alone of the brilliant and sadly buried movie version.