Megaguirus is almost as uninteresting as Godzilla's son was on terms of characters within the Godzilla universe. The encompassing attraction of the Godzilla franchise is the slam-bang monster madness and Megaguirus doesn't satisfy, that is, until the last 5 - 10 minutes of the film where in a cop out twist, Megaguirus reaches his final form. Note to Toho: This isn't Dragonball Z. The origins of Megaguirus revolve around an insect that was featured in Rodan called the Meganulon. The evolution/radiation clock ticks and little by little these creatures grow while posing a more discernible threat.
A clashing romance begins between the street-smart hacker/engineer and the stern feminazi named Kiriko. These two characters obviously fancy each other for reasons oblivious to me but I brave the romance plot line for as long as it takes for the disappointing action to build up. To intervene, the Godzilla story this time around is far more unrealistic than I'd expect a giant lizard film to go. The preferred method of getting rid of Godzilla is a space gun that shoots mini-black holes that reminds me of the alternate ship battles in Skies of Arcadia.
When the "vs." finally takes effect, the Meganula finally evolves into Megaguirus. A fossilized dragonfly dinosaur hovers above Tokyo taunting our scaly anti-hero. In a disappointing battle, the only true applaudable effort is the effect for the Megaguirus. In a surprising turn of events, Godzilla's methods of dispatching the villain proves to be irrevocably bad ass. Godzilla vs. Megaguirus doesn't fare well compared to some of the above-average entries. You can thank the clear storytelling that would rather focus on embarrassing characters instead of the implied title.