Nobody expects a Gundam show to be funny. SD Gundam commits to the bit so hard that it stops being a parody and becomes its own thing entirely. You're watching a mecha comedy where the jokes land because the show treats absurdity with total sincerity. The OVA format lets it move fast. Six episodes means no filler, no padding, just pure comedy timing and character bits that stick. The real draw isn't the mecha designs or the sci-fi setup, it's watching a show that knows exactly what it is and refuses to apologize for it. This one is built for people tired of Gundam taking itself seriously. If you want to watch tiny robots get into ridiculous situations with actual comedic craft behind it, this scratches an itch nothing else does.
Kidou Senshi SD Gundam Mk-III is a 1990 mecha and sci-fi OVA.