Gamera: Super Monster, the last of the Showa-era Gamera movies, largely comprises of clips from the previous films (although there is also footage from a couple of unrelated animated films as well), with new scenes to tie all the battles together: three super space women, defenders of Earth, befriend a small boy and do battle with an evil woman from the Pirate Spaceship Zanon, who sends several monsters (Gyaos, Ziger, Vira, Jiger, Guiron and Barugon) to wreak havoc on Earth. Of course, giant spinning turtle Gamera is always on hand to give them a jolly good thrashing.
If you've already seen all of the previous Gamera movies, then Super Monster will be a crushing bore, Gamera defeating one monster after another ad nauseum before sacrificing his life by smashing into the Zanon spaceship (which looks suspiciously like a Star Destroyer from Star Wars). The nonsense in between the battles sees the three good space women, Kilara, Mitan and Marsha, beaming from one place to another and transforming from human to superhero by performing a stupid series of arm gestures; meanwhile, kid Keiichi releases his pet turtle into a river, plays his Yamaha organ (whilst singing the Gamera March), and is pursued by the evil woman, who hopes that the lad will lead her to his three female friends.
Produced by a struggling Daiei Studios as a last ditch effort to make enough cash to stay afloat, the film is so sloppy in all departments that it proved to be the final nail in the coffin instead.