Some films are merely bad ("The Avengers"). Others are enjoyably bad (Showgirls). Some films are so bad that watching them is physically painful. "Santa Claus Conquers the Martians" is one such special case.
The plot, such as it is, proves it is possible to insult the intelligence of a three-year-old. Kimar (or King Martian) and Momar (or Mother Martian) have kidnapped Santa Claus to provide some much needed festive cheer for offspring Bomar and Girmar (work it out). However evil Voldar has other plans. Much tedious and stultifying mayhem ensues. The film ends with a teeth-grinding theme tune "Hooray for Santy Claus", which was obviously not the perennial Christmas hit its makers had anticipated.
Scripting, acting, production values, and plot are universally risible. Sets are cardboard, Martian costumes improvised from kitchen implements. Amusingly, the film features a youthful Pia Zadora in her first role, obviously starting as she meant to go on. Most amazing is the po-faced seriousness pervading the entire affair. The makers obviously believed they had a winner on their hands. The wonder is that director Nick Webster ever worked again. In fact, he went on to make gems such as "Red Planet Mars"(1968) and "Manbeast! Myth or Monster" (1978).
Apparently Ben Edlund, who co-scripted the dreadful "Titan AE" (along with "Buffy" maestro Joss Wheedon, among others) is planning a re-make. Whether he can do anything with such unpromising material is debatable.
To sum up, this is quite possibly the worst film ever made. Throughout, one felt an urge to hurl buckets of foetid offal at the screen. Avoid, unless you collect bad films or have a strong stomach.