Finally re-watched this film for the first time yesterday and, while it held up better than my first viewing, I'm still not too fond of the film. The music score here is the best part, although the usage of Ifukube's music is, quite honestly, tacky and unnecessary. The acting here is good, but the characters are pretty flat so the actors aren't given much room to work with. Finally, the big fight between Godzilla and Megaguirus is admittedly fun. It's energetic, inventive, and exciting.
As for the negatives, there are...quite a few. First off is just the dubious amount of plot holes in this film. IHow can our lead survive the radiation from Godzilla's body when she grasps onto him? Why did the kid grab the egg and was then intent on getting rid of it so quickly when he got to Tokyo? Why was Megaguirus never mentioned again after her defeat? Was her role in the film that trivial in the grand scheme of things? Finally, how in the HELL could Godzilla stop a black hole with his atomic breath? It's a black hole, the breath should've been sucked in...then again, it IS Godzilla.
The SPFX are extremely crummy too. The CG is dreadfully bad, the suits and props are stiff, the miniatures are unconvincing, and so on. From a special effects standpoint, this film is one of the laziest looking ones in the franchise.
So yeah, while it may no longer be my least favorite Godzilla film, it's still in my bottom five. I just can't bring myself to enjoy this one considering I love the '70s films to death. Maybe it's because those films weren't really trying to be anything more than just kid's fare whereas this one aims at a more mature audience.