I actually find the parts that aren’t stock footage in Gamera vs Viras to be some of the most fun and creative parts of the series. Opening with a battle in space between Gamera and a spaceship was cool. And it was interesting seeing Gamera acting like an unreasonable destroyer making a pre-emptive attack on aliens that he has no way of knowing are invaders, in a way that mimicked the cinematography of his first film as a villain where he burned a whole room of dancers alive.
Gamera is really a pretty morally ambiguous monster despite him becoming friendly to humanity, he’s. But since he’s a giant turtle you can’t really expect him to know right from wrong.
I just wish we didn’t have the most awful kids in this one. They did win back some points when telling the military to just shoot them along with the aliens being willing to die.