The episode leads off with not one but two chapters of the "Commando Cody and the Radar Men from the Moon" serial, which if nothing else clearly demonstrates how the serial seemed to try just a little too hard to set up its cliffhangers, showing the hero's car or plane crashing in flames at the end of one chapter but at the start of the next going back to show how he actually bailed out instants before impact. The early "riffing" somehow doesn't quite make the serial seem more exciting than it is; both Josh Weinstein's jaded Tom Servo and Joel sound a little bored to start with. They seem to be warming up by the time they get to the movie proper, though, and the movie itself most definitely helps.
Clearly set up as a dream sequence, the minimalist post-apocalyptic goings-on of "Robot Monster" do have their own charm, with bizarre dialogue, a bombastic and distinctive score by Elmer Bernstein, and the memorable Ro-Man, somebody ambling around in a bulky gorilla suit with an improvised diving helmet-like head, wearing a stocking over his face. (Joel comments that it looks like "a bunch of clay" inside the helmet as our heroes get into the spirit of surrealism during the host segments. I was somehow intrigued by the references to Isaac Asimov during them, which also showed up in another first-season episode. In addition, Tom Servo's bubble head "explodes" when he get confused... something that MSTings could sometimes carry to excess.) There's one point that did leave me thinking ahead: as part of the general chaos leading into and out of the dream sequence, there's some repeated stock footage with really cheap stop-motion animation of dinosaurs and two actual lizards gruesomely attacking each other. I believe that an episode of the second season had something approximately the same, and that time our heroes start getting upset about it.