This short film was directed by Takuya Uenishi and is an official Toho-produced sequel to Uenishi’s fan-made short film G vs. G. That movie was entered into the 2019 Godzilla contest and he was given the opportunity to develop a sequel project with Toho as his winning prize.
In the future, a place nearly twenty-five years since the last appearance of kaiju. he human race is fresh meat for several Gigan until one of the monster’s dead bodies is thrown at them. In the foggy distance, Godzilla appears and fights off three of the Gigan and their buzzsaws before they give their energy to the Gigan Rex and the battle rages.
According to TV Tropes, the Godzilla in this movie is a grown-up Godzilla Jr., with the first shot being similar to his resurrection Godzilla vs. Mechagodzilla II. His lullabye theme plays as well. He uses the Heisei era Nuclear Pulse and also has a Super Mode like Burning Godzilla. This also has narration from Megumi Odaka and has similar words to a speech in Godzilla vs. Destroyah.
Takuya Uenishi also worked on visual effects for Godzilla Minus One and created another short last year, Godzilla vs. Megalon.
I loved this! Toho has been awesome about how their trying to expand the Godzilla brand more creatively with their contests. This is just another example of the great things that come out of that!
You can watch this on YouTube.