What kills this movie is the overuse of stock footage. It's one thing to lift a few bits from Ghidorah or DAM and stick them in among the original action footage in Gigan or Megalon (annoying, but tolerable), but most of the action sequences in this movie are 100% stock footage. I don't mind that a kid dreams about visiting Monster Island or Minilla talking, the stock footage overkill is what kills this flick for me. Even as a kid, I had seen all of these fights shot for shot before in better movies. If I want to watch Godzilla's fights with Kamacuras, Ebirah, the jets, the giant condor, or Kumonga, I'll watch the much superior Sea Monster or Son of Godzilla.
Godzilla's rumble with Gabara is great. If all of the action sequences in Revenge boasted original effects footage, with newly staged battles against all of those aforementioned foes, then it could have been one of the coolest Godzilla movies ever. As it is, it just falls flat.