So basically this is Godzilla's cousin in a shell and like his more famous counterpart Gammera also enjoys slowly smashing his way through half of Tokyo. This version of the film adds some American characters to add a more international air to the Japanese original though it doesn't add a great deal to the story. At the end of the day it is still a man in a rubber suit crushing model buildings.
The film is fun but frequently ridiculous. Including the music that appears to rip off the Batman theme. The main problem with Gammera in this film is that he isn't very scary, he just seems to waddle around destroying things by accident.
