third Gamera movie, and it starts the theme of having a child in a leading role. it was released to American tv in the late 60s, probably '68 or so. I never saw it as a kid, so it doesn't quite have the same impact as some of the later ones did. I saw it in the late 80s when Sandy Frank released it along with four other Gamera movies.
it does boast some of the best effects of the the series though, with plentiful destruction scenes and some interesting monster fights. Gyaos has cool powers and who knew then it would be the most overused monster in the Gamera series?
the kid isn't the best child in the series, but he's OK. I love how "Operation: ...." is a running theme in many of these movies.