As to Gumonga, the opening and closing of the mouth was operated by remote control. The shell Alien Bell had on his back was made by being cast out of the same mold as Gumonga while it is unknown why the alien has the shell shaped like Gumonga on his back.
Gumonga’s face with the big eyes and big mouth like a cartoon character might look too humorous for a spider monster dwelling in the mysterious mock space.
For the scenes in which the Ultra Garrison members fell down with parachutes and Amagi and Soga looked up at Earth in the sky, the front screen projection to project images over actors onto the background is said to have been used instead of the rear screen projection to do the opposite.
The clear combined images seem to have surprised the staff when the film was shown.
It is explained the scenes of the forest where Amagi and Soga wandered around were filmed in the woods that used to be located in Fuchu City, Tokyo, and the ones of the bottomless swamp were shot in the now-defunct outdoor studio possessed by Toho named “Ikuta Open” in Kanagawa Prefecture.
The set of Vallarge is said to have been built in Ikuta Open for Ultraman Episode 7 while the set was originally for the 1966 Toho movie titled “Adventures in Kigan Castle” starred by Toshiro Mifune.
While this episode was concluded by a line uttered by Captain Kiriyama that goes like “wisdom without God will raise the devil with wisdom,” there is an explanation it came from the words “intellectual training without God will raise the devil with wisdom” inscribed in stone at Tamagawa University Tetsuo Kinjo who wrote this episode graduated from.