Yes, this is the movie where Godzilla does his little dance of joy, completing his anthropomorphic change from mindless instrument of destruction to sentient hero. The sixth entry into the series also marks a shift from 'horror' to 'science fiction', as "Invasion of Astro-Monster" opens with some nonsensical 'space talk' while a rocketship carrying two astronauts (Glenn and Fuji; Nick Adams and Akira Takarada respectively) travel to a newly discovered moon of Jupitar (christened 'Planet X'), only to find it populated by 'Xians' and besieged by Ghidorah. The Xians offer a cure for cancer in exchange for permission to 'borrow' Rodan and Godzilla, whom they plan to use to eliminate the Ghidorah threat, or so they claim. Suspicious events are occurring on Earth and the astronauts sense that there might be something malignant behind the Xians benign offer. In this film, the now sentient saurian is a full-fledged hero - recruited by the Xians to fight an evil monster and later defending the Earth itself. His original transgressions seems to have been forgiven or forgotten (Fuji, who feels sorry for leaving the Earth monsters on Planet X, comments that Godzilla and Rodan "cause troubles sometimes" - a considerable understatement, considering that, over the years, they have destroyed the cities of Fukuoka, Osaka and Tokyo, presumably at the costs of thousands of lives and billions of Yen). Notwithstanding Godzilla's infamous victory jig after his initial routing of Ghidorah, the film* is not played for laughs as much as was "King Kong vs. Godzilla" but remains a pretty juvenile outing, with a 'good guys vs. bad guys' plot, simplistic characters, an inconsistent (and at times nonsensical) storyline, a silly script, and lots of monster fights. The decline in the series' budget is apparent as most of the brawls are on the desolate Planet X or in unpopulated parts of Japan rather than in the complex (and expensive) city sets that were common in the earlier films and gave some sense of verisimilitude to the inherently unrealistic suit-mated monsters. There are some good parts - I like the spaceships, the alien 'airlift' of the monsters, the almost surreal scenes on Planet X with Jupitar looming in the sky, and as always, Ghidorah makes for an entertaining foe. Overall, very watchable by fans of the genre but pretty much what most non-fans would expect to see if invited to join in: another goofy Japanese monster movie. *This review refers to the subtitled Japanese version; however, as the film was an American-Japanese coproduction (hence American co-star Nick Adams), there is little difference between the subtitled and English dubbed versions.

A couple of moments in "Invasion of Astro-Monster" show great promise. The first comes during the first appearance of King Ghidorah, with a cascade of gravity beams shown on the screen behind the Xien leader as he explains the situation. The second comes when the Xien spacecraft transport Godzilla and Rodan into space. Both of these show the two intended genre elements working in harmony, and had the rest of the movie followed suit this might have been a seminal entry in the series. Unfortunately, the results are too lopsided to work. Complementary genre elements are of little use if they supplant what unique things are brought by the giant monster genre, especially when said elements have been done much better in past films.Simply put, "Invasion of Astro-Monster" does not feel like a Godzilla movie. Too much of the running time is devoted to the human/alien conflict, and while this does lend more substance to the human portion of the narrative, it's still clumsily constructed as in any entry of the series. Various ideas are either truncated or plumb never capitalized on, such as the Xiliens' deception, which is made blatant both to the audience and some of the heroes, and explorations of the Xiliens' culture are mostly limited to throwaway details. The pacing is nothing to emulate. Scenes on Planet X seem to go on forever for the sake of imitating "Forbidden Planet", and the multiple trips between Earth and Planet X seem unnecessary. The point is, "Invasion of Astro-Monster" never gives us an alien invasion plot capable of carrying an entire film on its own, and this issue magnifies the already fundamentally disappointing decision of reduced monster action. If one is to endure the downplaying of the monsters in a monster movie, it's only fair to demand something superb. But, it's difficult to not make comparisons with other alien/space exploration features (e.g. Forbidden Planet, War of the Worlds, Earth vs. the Flying Saucers). The conflict with the Xiliens, with its lack of outstanding qualities, needs the monster element to stand out, and that is unfortunately what the film fails to capitalize on. Treatment of the monsters is, on the whole, poorer than in the previous entry. While their destruction scenes are adequate, if repetitive, these guys always feel like mere appendages to the plot rather than focal points of concern; they're regarded as assets rather than creatures. Say what you will about the incipient goofiness from "Ghidrah, the Three Headed Monster", but at least these guys had an established presence in that movie, with actual signs of personality. Here, they don't even get a proper send-off, instead suffering from that head-scratchingly unceremonious ending. There are some good moments, though. Namikawa's sacrifice is moving, and the self-destruction of the Xiliens is certainly dramatic. Additionally, Akira Ifukube delivers a great new rendition of one of his themes from Godzilla (1954), which can be heard over the opening credits. Even so, as far as I'm concerned, this is a pretty middle of the road effort for the Godzilla timeline spanning the 50's, 60's and 70's. It's strengths elevate it above utterly disposable products, like "Godzilla vs. Megalon" and "Godzilla's Revenge", but time has not been very kind to it; later films would incorporate aliens in more ingenious and entertaining ways.

It's one of those Godzilla movies where you fully understand why some fans of the "Zilla" series positively dislike it. The big atomic lizard is only a bit part player here, and when push comes to shove the monster mayhem is in short supply, which considering we also have Ghidorah and Rodan in the mix is for sure a bit of a waste. Yet this is one of the better sequels from Toho's original wave, it quite literally has all the ingredients that made "Zilla" and the off-shoots so iconic.We are in live action cartoon territory, a sci-fi story of bonkers proportions yet engrossing all the same. The joyous model work synonymous with the series remains intact, the cardboard sets being obliterated are still fun to watch, and the divisive sight of "Zilla" doing the "shay" dance is in here whether you like it or not. More fun, though, is watching "Zilla" boxing the three headed Ghidorah, now that is comedy gold, if only the moody lizard had gone southpaw a bit earlier then saving the world could have been achieved quicker.Great fun, could have been better from a monster point of view? Yes, definitely, but this be a nutty fruitcake production from Toho and amen to that. 8/10

This movie came a year after the debut movie for King Gidhra "Sandai Kaijyu Chikyu Saidai No Kessen", and takes another attempt at having multiple Earth monsters against the Gidhra.Astronauts Fuji (Akira Takarada) and Glenn (Nick Adams) are on their way to first exploration of Jupiter. On their way, they discover a new 13th satellite of Jupiter that gets named "Planet X". The two land on Planet X and discover that it's inhabited by people who are more advanced than Earth. The planet is also inhabited by what they call "Monster Zero aka King Gidhra". People of planet X request help of Earth monsters Godzilla and Rodan to exterminate King Gidhra, and in return they offer a cure for cancer. Fuji and Glenn return to Earth and report the incident, but the tape containing the message from Planet X turns out to be an invasion notice to people of Earth. Planet X uses Godzilla Rodan, and King Gidhra as weapons to destroy Earth. A novel solution to this problem comes from Fuji's sister Haruno (Keiko Sawai)'s fiancé Tetsuo (Akira Kubo). Due to this solution, Godzilla and Rodan, now free from Planet X's control battles King Gidhra (again).This movie titled "Kaijyu Daisensou" in Japan features 3/4 of the monsters that appeared in the previous Godzilla movie "Sandai Kaijyu Chikyu Saidai No Kessen" namely Godzilla, Rodan, and King Gidrah (minus Mothra), and is almost a sequel to that movie. King Gidhra that got booted out of Earth on the previous movie ends up on Planet X. Godzilla and Rodan decides to hibernate for a while, until Planet X guys comes to wake them up. Although such connections are not implied in this movie, the two movies connect seamlessly.Production wise, this one is a notch below that of the previous movie that's regarded as one of the best Godzilla movie from the '60s. The characters are not well fleshed out as they were in the previous movie which makes the story rather bland. The scene changes between Earth and Planet X's base is not handled well, and takes away from the plot of the movie. If they were able to handle the scene changes better, and exploit the characters a bit more, the story would have been a lot better.Addition of Nick Adams and Kumiko Mizuno also didn't add much to the story. They did much better on "Frankenstien vs Baragon" (Frankenstein Conquers the World).So the movie could have been better, but it's still a good middle of the road monster movie from good folks at Toho.