Saw the movie on TMC and it was indeed a classic. Everything about this film is bad, ranging from Robert Horton's (late of Wagon Train and 110 degrees in the Shade) hairstyle, to the acting to the incredibly cheesy special effects, the "Cousin It" monster (mentioned in one of the comments below). Even the colour they used for outer space was wrong. It was made in the late 1960's (around the same time as perhaps the greatest or certainly one of the greatest sci-fi films of all times: 2001) showing the future with technology that would have been dated even then. I've been watching a lot of films on TCM, including many of the best ever made, but I found this to be just as entertaining an hour and a half as almost any I've seen. Right up there with "Sata Claus Conquers the Martians."