purkka’s review published on Letterboxd:
If you (VERY UNWISELY) decide to marathon the entire Bionicle G1 trilogy (there's a fourth one that is so bad it doesn't even deserve to be called a movie), this is the one you'll look forward to. The visuals are a massive improvement from the horrifyingly ugly first installment, and just in terms pacing, storyline, and character arcs, it feels like an actual movie most of the time!
Thanks to massive increases in either budget or the talents of the people involved, most of the character designs and urban environments of Bionicle 2: Legends of Metru Nui are well-realized, and it's just pretty good at crafting decently compelling images. Vakama's visions that both foreshadow and repeat scenes are a nice reminder that the movie does have at least a couple of shots worth looking at. There's more variety to the action scenes, too, and most of them are animated well enough, even if the final battle is once again pretty lame.
The screenplay juggles between six main characters in a surprisingly competent manner. While trying to unlock or master one's magical powers is a pretty unexciting stock conflict for this kind of thing, it at least creates a convincing impression that the characters develop and go through psychological change. Between this, some fun secondary antagonists, and the comedy being a lot better, the average character interaction in the movie is not unbearably annoying to watch! Wow! Mission accomplished!
Forming something of a trend for this franchise, though, the weak point in the writing remains that the antagonist's goals and motivation are impossible to understand – there's a legendary artifact with powers that are neither explained nor shown, and its true purpose remains a mystery. While this is the peak of the trilogy in many ways, at least they finally solve the "the plot makes no sense, like at all" problem in the third one. Still, it's definitely the good one, for a very relative definition of "good".