Kill every cockroach you see.
I'm finding it harder and harder to give objective scores to Godzilla films. The simple truth is that most of them sit somewhere around the same level of respective quality. Godzilla vs. Gigan is another film in the series that falls somewhere between mediocre and entertaining, but that's about as good as you can hope for with the original set of Godzilla films. On simple entertaining destruction and campyness alone, Godzilla vs. Gigan is one of the more enjoyable films of the era.
Get this, evil alien cockroaches from outer space are planning on taking over. They're going to mind-control some space monsters and it's up to Godzilla and random earth monster #154 to save the planet. Luckily, hippies are on Godzilla's side and, with their help, everything turns out OK. Jun Fukuda is back in the director's chair after a five year absence, but after the awesome shift that Godzilla vs. Hedorah, the previous film, might have inspired, Fukuda's direction is pretty disappointing. Godzilla vs. Gigan is commonly listed amongst the worse films in the series, but I just have trouble buying the hatred.
It's obvious that Godzilla vs. Gigan is not great. It's low budget, even for a Godzilla film, and the plot and dialog are pretty much incomprehensible, but it just packs enough awesome camp to keep me entertained. Stupid stuff like the monsters talking, which probably would have bothered me if I had watched a dub of it in English, and the corn-cob wielding Japanese hippie make me chuckle. The fights are pretty decent, even if there is a little too much stock footage being used, but the destruction Gigan and Ghidorah cause right after they appear is fantastic. That destruction sequence alone makes the rest of the movie almost worth watching.
OK, you're right. Godzilla vs. Gigan is not the series at it's best. The film has obvious flaws, but I'm going to be daring and say that I don't care. I would still rather watch this film over a vast majority of the other early movies. The mistakes and goof-ball writing make it kind of fun. I'm starting to look forward to getting out of the early era of Godzilla films. I'm finding them all quite underwhelming and familiar. Godzilla vs. Megalon is next and it's a pretty awful piece of film-making.