An empty yacht is discovered in Tokyo Bay that contains research claiming that a gigantic creature, known as Godzilla, will soon rise from the ocean. At first, the Japanese government is skeptical of both the research - but when Godzilla rises, it becomes clear that it's real.
Monster movies have always had a deeper layer and subtext to them. The original Godzilla was made in 1954, just nine years after Hiroshima and Nagasaki, and the creature Godzilla then became associated with nuclear weapons and the terror it caused on Japan. Since then, Godzilla has gone through various shifts in theme and design, but the idea of Godzilla as metaphor has always remained. Look at Cloverfield and how it relates to 9/11 and it's the same idea. With Shin Godzilla, the monster and the destruction it leaves behind is clearly paralleling itself with Fukushima and the 2011 Tohoku earthquake and tsunami. However, what makes Shin Godzilla so interesting is that it not only parallels this, it also parallels the real-world response.
The vast majority of Shin Godzilla doesn't necessarily focus on the devastation wrought by the creature, but how ineffective the bureaucracy of Japan is at stopping it, or least slowing it down. The film cuts from meeting room to meeting room, as gravel-faced politicians talk in broad terms about the destruction and recommend plans of action and press conferences, all of which serves to push the frustration of ineptitude with government response. It's only when a young go-getter called Yaguchi decides to form his own team that anything begins to happen. Yaguchi's team is made of "weirdos and loners", but they're effective and the free flow of information and ideas between them is in direct contrast to how ordered and staggered the previous attempts at stopping Godzilla were.
What the film lacks in character development, it makes up for both in pacing. While it might not have the extravagant budget of the Western version of Godzilla, the film instead uses clever editing to show the panic and terror caused by the creature. The use of phone and news footage is easily interspersed with the actual carnage caused by the creature. Moreover, the way in which it's captured is eerily reminiscent of the actual footage from Fukushima. This manages to ground the film in reality in a way that Gareth Edwards' version never did, and it serves to make the creature all the more terrifying. That said, when you first see the monster, there's a certain amount of surprise in that it doesn't immediately look at how you think Godzilla - but the film uses this as a way of moving the story forward and serves a purpose. Audiences who are used to seeing the classical representation might find it a bit funny or comical-looking, but this doesn't last for long when the creature begins to form and take shape.
Watching Shin Godzilla, there's no doubt a lot of elements of the story that might flow over the head of Western audiences and subtle nuances and references may go unnoticed. What makes the film so well-made, however, is that even if you're only getting one half of the story - i.e., giant monster ripping up Tokyo - it still works perfectly well on that front. When you view Shin Godzilla through the prism of its intended metaphor, it gets even better. While it's unfair to compare it to the US version of Godzilla as they're operating on two different wavelengths, Shin Godzilla nevertheless has much more intelligence and meaning than the US one, which makes for a more engaging and compelling film, and shows up the current batch of monster movies for their lack of substance.