- Franchise Killer: The film's low box office attendance marked the end of the 21 years long original Showa series run, and put the overall Godzilla film franchise on ice for nearly a decade, before it was revived with the beginning of the Heisei series in 1984.
- Edited for Syndication: The television cut by UPA, which was chosen for the Classic Media DVD release as the included english version. While not Bowdlerized to the same extent as the theatrical release (there's a shot of Katsura's bare breasts that was edited out, and nothing else), this version also adds a bizarre prologue with narration recapping the past Godzilla films over stock footage of the other two Godzilla films UPA had the rights to (Invasion of Astro-Monster and All Monsters Attack. Since the latter was itself a Stock Footage-filled movie, this meant they were also using footage from Ebirah, Horror of the Deep and Son of Godzilla).
- Enforced Method Acting, Throw It In: During the climactic battle, one of the explosions sets Godzilla's spikes on fire. Either from the force of the explosion or from the fire itself, Toru Kawai was startled by what happened, giving Godzilla an extremely apropos moment of freaking out in the final product!
- Refitted for Sequel: Some of the elements in this film may have been used from the original concept of the original Godzilla (1954): An old scientist discovers an undiscovered ancient beast near Japan, reveals to be a Mad Scientist, sabotage the military's efforts to defeat the rampaging creature, and his daughter thwarting his plans as this is going on.
- What Could Have Been: Though the ending seems pretty climactic, this film was never meant to be the last entry in the Showa era; a number of attempts at continuing the series were carried out through the remainder of the 1970's and into the 1980's, but never managed to progress much further than the concept stage. Some of the more notable casualties of this period are 1977's Godzilla Legend: The Asuka Fortress, 1979's A Space Godzilla - which happened to be preserved after making the jump from film to short story - and the 1980 and 1983 concepts for Resurrection of Godzilla, which were the first attempts at introducing Bagan to the franchise.
- Word Of God: Series creator Tomoyuki Tanaka in his Godzilla fact books stated Titanosaurus did indeed survive getting blasted off the cliff by Godzilla in the end. Now free of the mind control, the dinosaur went back to peacefully living in the ocean depths.
Trivia / Terror of Mechagodzilla