There have been two versions released in the US, one back in the 1960s called GAMMERA THE INVINCIBLE and one, for home video in the 1980s called simply GAMERA. The earlier version was treated much like GODZILLA KING OF THE MONSTERS, with inserted footage of American scientists and generals.The dubbing was well done and the editing was good.
The second was pretty much as Daiei made it, with laughable US army personnel who CLEARLY could not act, included for the foreign market. The dubbing script was also incredibly bad and extra nonsensical. This is the infamous ‘Sandy Frank’ version that found fame on MST3K.
Gamera would see seven more films in his first series, through the late 70s, before coming back in an all new re-telling in the 90s. After the first two or three, they were more clearly geared towards kids, with Gamera always saving the day from another monster.
Happy birthday ‘Little G’.