This is the third helping of Gundam refusing to take itself seriously, and by 1990 the joke had been sharpened into a weapon. You already know the drill from what came before: Amuro, Kamille and Judau bickering over whose pension is better until Char crashes the party, the SD Olympics turning mobile suits into track and field props, an entire colony rolling out of control because the boys lost their minds over a cabaret act. Mk-II went full RPG parody with Gundam Legend, sending the three of them on a fetch quest for a princess with Char cast as the boss fight. Mk-III keeps the format that made those work: short, plot-first sketches where the cast exists to serve the gag, not the other way around. If you can recite One Year War lore chapter and verse, this is the show that mugs you for it and expects you to laugh. Six episodes, no ceremony, chibi Char still stealing every frame.
Kidou Senshi SD Gundam Mk-III is a 1990 mecha and sci-fi OVA.