If you're a fan of Gamera from '90s trilogy, Gamera vs. Barugon may be the original Gamera movie for you.
The movie begins with Gamera's being freed from the rocket he was trapped in at the end of Gamera, the Gigantic Monster and returning to Earth to wreak havoc on a dam. He then disappears for a good 45 minutes while the movie follows a trio of treasure hunters to a tropical island on their quest to retrieve an opal the brother of one of the hunters hid in a cave during the Second World War. Not to give away too much, but the procurement of this opal leads to the emergence of Barugon, in the middle of Japan, who Gamera (eventually) fights in typical Gamera fashion.
Three things immediately stand out about the second entry in the Gamera series:
There are no kids in this movie. As in its predecessor, Gamera is apparently motivated purely by a quest for energy sources.
Gamera is barely in the movie. He opens the movie, returns to fight Barugon, then comes back after another long absence to fight Barugon again. The bulk of the movie deals with the birth of Barugon and the Japanese's attempts to defeat him. (Maybe this was the genesis of the military's conflict in Gamera: The Revenge of Iris over which monster to attack first.)
Finally, the movie is in color, and Daiei seems eager to exploit that fact. The opening titles are played out over shapeless colors, and one of Barugon's weapons is a rainbow beam emanating from his back.
The movie contains some silly moments (most notably the theft of the diamond), but the human conflicts and relationships are played surprisingly straight and adult, at least in comparison to those in a typical Godzilla movie; everyone doesn't necessarily agree on strategy, and it's probably safe to say the two leads don't view each other as siblings. The biggest problem with the movie is its odd pacing, but without a delusional kid and several characters who do virtually nothing running around, Gamera vs. Barugon is a decided improvement over the original.
