Many of the background players are American military personnel who were based in Japan at the time.
On-screen deaths: 6.
Production manager William Ross would often serve as translator between the Japanese film crew and the American actors.
The cover of 1983 science fiction book 'The Worlds of H. Beam Piper' was based on a scene on the asteroid in this movie.
The green slime creatures were played by Japanese children in bulky monster suits.
The theme song was covered by Josie Cotton on her 2007 album "Invasion of the B-Girls".
This film is listed among The 100 Most Amusingly Bad Movies Ever Made in Golden Raspberry Award founder John Wilson's book THE OFFICIAL RAZZIE® MOVIE GUIDE.
This was the first film ever to be featured on the cult TV series Mystery Science Theater 3000. An edited version of the film appeared on the show's never-aired pilot episode.