Considering that this film was made in 1963, in Czechoslovakia, at a time when so much sci-fi schlok was produced in the spacefaring United States, this film is a rare, welcome sight to the eyes. Intelligently produced and designed, with good character development and good special effects, I miss seeing this film which seems to have been lost in the Great Transition To Video; I know of no distributors for it. It does have its corny moments, but this is excusable in light of the time in which it was made. The ending was unfortunately changed for U.S. viewers, which is a shame; It is the U.S. ending which gets criticized most...I imagine the European ending would have been more in keeping with its originality, and would hope that American International would re-release it in the U.S., with new dubbing (I'm one of those non-purists who can't stand sub-titles...they interfere with the enjoyment of the image. And yes, dubbing CAN be done well, when done RIGHT!). It's been nineteen years since I saw it over the airwaves. I hope it has not vanished; It would be a shame for others not to experience it.