"Frog-g-g" is an intentional spoof of pre-CGI monster movies, and as such is a mixed bag. At times it takes itself a bit too seriously, but at others is intentionally campy. The plot is as old as cinema itself: evil business tycoon dumps toxic waste into the town water supply creating a strain of giant killer amphibians who need to spawn. What I am saying here is that the giant frog is extremely attracted to human women, which, naturally, leads him directly to the St. Mary's Catholic School For Girls. There is a corrupt Sheriff (the brother-in-law of the businessman, of course) and a romance subplot. In other words, it's exactly what you would expect from a silly guy-in-a-rubber-suit monster movie from the 1970s.
Sometimes the spoof works (normally when it is being more intentional) and sometimes it just drags. There is a lot of high school football shown (some might crassly call this padding) and eventually the frog man does invade the football game. I have a couple of favorite moments from the film, the first was in the opening credits: I knew I was in for a rough ride when I saw the credit "Music by The Glam Spice Generation." Although unable to top the music credit, I did enjoy that the frog killed a nun instead of procreating with her. When asked to explain this unusual behavior, our heroine, EPA super agent Barbara Michaels, says that "he probably sensed a low estrogen level."
There were also some things that I did not like about the film, notably the inability to fast forward through the previews, and the frog-human hybridoma birth at the end of the film, which was both predictable and unnecessary. It did feature scream-queen Mary Woronov as a gynecologist delivering the little biology experiment, which was a bit of a B-movie coup for the production. In another unexpected touch of "class," there is a short on the making of "Frog-g-g" as well, something not frequently seen in this league.
The film is somewhat entertaining on a camp level. I would recommend it more highly if it were more focused as either a humor or satire piece, and if it did not feature a giant frog breakdancing during the closing credits.