Since this film is in continuity with the Japanese television series, I won't rehash all of the changes made from the US version. I discussed that in my review of the television series here.
Essentially, this "film" was just like any other episode of the Japanese Spider-Man TV show except that it was filmed in widescreen. The length of the movie is 23 minutes - the same as the average Japanese Spider-Man TV show. Even the introductory title sequence is the same (except portions are cut off because of being fitted to widescreen). The show is without the transitions that would normally go before and after the cuts to commercial. At the end of the film, a "The End" card is displayed.
The plot revolves around an Interpol agent, Mamiya Juzo. Juzo has discovered Spider-Man's secret identity and has a mission for him - stop the Machine Bem, Sea Devil, who has been blowing up oil tankers. Perhaps the thing that makes this movie most different from a normal episode is the introduction of Juzo, who is then becomes a reoccurring character in the next few episodes of the series.
The production value was really stepped up for this movie. The highlight is a helicopter sequence that has Spider-Man dangling from the helicopter, just barely able to hang on. Sets and camera work are much improved as well.
Still, those changes do very little to improve the overall quality of the storyline. It's still a Power Rangers episode that happens to star someone dressed up like Spider-Man.
1LR Review - 6 out of 20! It's a Faliure!