You must agree that at least the film has some impressive special effects, or did have until 2001 A Space Odyssey came along in the same year, but it does have impressive special effects for the year it was actually made: 1964. Most of the film, the bits with the men in them, is from a pretty good Russian film called Planet Of Storms made in 1964. Because Russia wasn't a signatory to the Berne copyright convention, Roger Corman got his hands on the film cheaply and made it into two films - Voyage To The Prehistoric Planet and Voyage To The Planet Of Prehistoric Women. Unfortunately the one time they were on a double-bill together, the patrons couldn't enter the cinema because the marque blocked the entrance.
—Nigel Honeybone