A positive in both films is that much of Godzilla's destruction is filmed in night scenes, in black and white, as this heightens what the viewer can imbue. The imagined is always more frightening than the real. This goes for Godzilla, the monster itself, for in the cross-cuts from rubber suited man to miniatures, matte paintings, and puppets, Godzilla seems to be a shapeshifter, a preternatural beast, and not the mere 'force of nature' other critics have lazily declared.
There are times we see pupils in Godzilla's eyes, and times when the monster seems like a white-eyed zombie or demon. A few years later, the great British horror movie Night of the Demon, directed by the inimitable Jacques Tourneur, would similarly make use of darkness to give its monster a shapeshifting feel, as well as hide its flaws in construction. (Perhaps in a bit of synchronicity, that film was also released in an American version that has been ripped as a bastardization: Curse of the Demon.)
Also, whereas later Godzilla films gave the monster a traditional dragon's fire breath, this beast spews atomic radiation in a mist that ignites fires, showing that the roots of Godzilla, in the extra-diegetic sense, was not in Japanese lore but in modern monster mythos. All of these effects were skillfully done by Eiji Tsuburaya, and despite the ridicule that subsequent Godzilla films have engendered, the original had better effects and was more cleverly shot — to downplay its shortcomings — than other monster films of its era.
Equally impressive is the score by Akira Ifukube. The opening footfalls of the monster are still as scary as any nightmare, and the main Godzilla theme, as well as those in other scenes, still resonate because they are fully apropos. Which of those two men — Tsuburaya or Ifukube — was responsible for Godzilla's trademark roar I don't know, but that roar is equally memorable.
The two-disc set comes with both versions on separate discs. Gojira is subtitled, while Godzilla is dubbed. Had Gojira been dubbed, it would have been a good bonus. Neither film was given a digital restoration along the likes of what The Criterion Collection usually does. Yet, especially in the American version, this is not a problem for it adds to the documentary feel of the film.
Another usually ignored plus found in the American version is that there is a subliminal dissonance between what we see — i.e., the cinéma vérité newsreel-like images — and the fact that Martin tells the whole tale in flashback, magically appearing at all the right moments in the film. That dissonance provides a dreamy quality to the narrative that the original lacks, something that is reinforced by the fact that he never really interacts with the main characters despite some quite skilled intercutting. In fact, Martin seems to exist outside the film, even when he is nearly killed by Godzilla. It's akin to having a lucid dream — that feeling that nothing can happen to the main character … you.
Even so, this dreamy narrative has a documentary-like approach. Such schism affects the viewer in ways not noticeable the first time around, but that feeling lingers afterwards. I've never known anyone who watched the original Godzilla and was not affected by it, positively or negatively.