Overall one's reaction to this film will rely on how interested they are in geology and plate tectonics. There are several points in this film where it grinds to a halt and we are "treated" to a lecture about how the earth's crust and mantle work and why the destruction of Japan is so imminent. While ostensibly quite boring, this actually perked up my attention as the whole scenario seems quite plausible. Japan is in fact in a precarious geologic position and could indeed one day (albeit over the course of millions of years) fall away into the Japan Trench.
This movie asks you to accept a huge what-if scenario for if continental drift could suddenly accelerate to cataclysmic rates. Fortunately this film also does a pretty good attempt to simulate this, relying heavily on Teruyoshi Nakano's brilliant pyrotechnic effects.
The real show-stopper comes about 40 minutes into the film with the out-of-nowhere 15-minute earthquake that strikes Tokyo and kills over 3 million people. What a bodycount! I think it had to be the largest in any film up to that point. Lots of quality shots of oil refineries exploding, cars crashing, people running around on fire, and even some surprisingly graphic gore when glass shards rain down on civilians. This sequence (along with the film in general) is aided immeasurably by one of Tetsuro Tamba's best performances ever as the stoic, yet prone-to-outburst prime minister.
Unfortunately this mid-movie sequence is the high point of the film. The climax is clumsily structured and not very exciting at all, instead deciding to focus on two married evacuees being separated. Quite disappointing. At least the film maintains a level of earnest seriousness which can draw you in even though there is little or no character development... much like VIRUS did seven years later. Also it asks some good questions such as whether a nation deserves to exist when the land underneath it ceases to be... or what human life (when we're not talking about a few, but 100 MILLION) is really worth.
Overall though, this film is a bit talky and poorly structured, but personally I was quite intrigued and not bored... and the mid-movie destruction and mayhem (as only the Japanese can deliver) was well-worth the price of admission. Also, refreshingly for Toho films of the time, there are no annoying children and no attempts at humor. Zero.
