- What Could Have Been: The film was originally going to be called "Godzilla vs. Astrogodzilla," and was to feature a completely different story:
- Astrogodzilla was to be an Albino Godzilla with wings, two tails, and Ice Powers (also confirmed to be created by Biollante's cells, instead of a toss-up between Mothra and Biollante.) Astrogodzilla kidnaps and hypnotizes Little Godzilla and Miki Segusa, using Miki as his personal translator, and holding Little Godzilla hostage. Godzilla, along with M.O.G.U.E.R.A. and Mothra, all team up to fight Astrogodzilla and save Miki and Little Godzilla. The film was planned to have a more showa-like vibe in comparison to the other Heisei films as well. However, after Toho's other film, Yamato Takeru bombed at their box office, Toho got cold feet and the film had to be heavily cut done into something much more run-of-the-mill, transforming it into SpaceGodzilla.
- Mechagodzilla was to be rebuilt from the previous movie, but Toho decided to use Moguera instead because they realized the film had too many Godzillas.
Trivia / Godzilla vs. SpaceGodzilla