Godzilla: Planet of the Monsters is the 32nd Godzilla film, the 30th Godzilla movie produced by Toho, and the first foray into anime for the franchise. Apparently nobody had the idea to make a Godzilla anime despite "Godzilla" and "anime" being in close proximity to each other for the longest time, but that's neither here nor there
The story goes that one day, giant monsters suddenly appeared on Earth and started cleaning house. And cities. And countries. And pretty much entire continents. Humanity somehow managed to fight off the appearance of kaiju after kaiju, until Godzilla himself emerged from who knows where and started obliterating everything from man to monster, pretty much taking the planet for himself or at least became the planet's overlord. Because of this, humanity is forced into space to search for another habitable planet, but the futility of their efforts forces them back to Earth where thousands of years have passed
From there, the story is "kill Godzilla and take back the planet." In terms of how much there there is in this film, there isn't a lot. It's a straight shot from point A to point B without an A-1, A-2, or A-4. It unfortunately means we don't get much in terms of character personalities, and the way the story is set, you'd be hard-pressed to have a swathe of expression without being incongruous to the mood. Which is actually the strongest point about this anime
Godzilla: Planet of the Monsters graciously keeps the humor to zero and isn't afraid to be sincere. It fires on all cylinders and avoids the failings of many dark anime. It's hopeless without being depressing, serious without being dry, and terrifying without being shocking. No, don't reread that because I meant what I said. Godzilla is an inherently hard creature not to idolize in terms of awe and spectacle, the number of films where he's genuinely scary can be counted on one hand; this movie is in their number. A combination of wide angle sweeps, low-angle shots, bone crunching sound design, and Gen Urobuchi's writing make every moment where Godzilla is on-screen just uncomfortable to watch; you root for the humans in this movie, which almost never happens
And for capturing what so few of his films have done alone, Godzilla: Planet of the Monsters is most definitely worth checking out. I can't say the human characters are little more than a vehicle to move the plot, but we're not traversing Earth anymore; we're exploring a planet of monsters