Concisely put, Santa Claus Conquers the Martians is the worst movie ever made.
See those colorful and jubilant Martian and Earthian children? The cool retro robot? The jolly, spaceship flying, Santa holding an overstuffed bag of goodies for all the good children in the universe? None of that is in this movie. What is, are Wham-o Air Blaster gun-toting Martian adults in desperate need of NoDoz, a fuddy-duddy Santa, dopey Elves, a dopey robot, Dropo the exceedingly dopey Martian, and even a dopey 800 year-old Martian-in-the-Cave doling advice to the NoDoz Momars and Kimars because their children want presents and holiday cheer and their own Santa.
It is colorless, lifeless, quite reprehensible and, yes, Virginia, the antithesis of that Christmas Spirit we strive to nurture the rest of the year: it is a lump of celluloid coal smudging black the delights of the season.