I'm a huge fan of the first movie, and of the original book. And I can certainly understand how this movie isn't liked in general and especially not by fans of the original one.
Still I wouldn't consider it a total "trainwreck", I think there are actually some very nice things in it that are, sadly, ruined by others.
Ultimately, it's a not-horrible cute-mice movie, but by far not a worthy sequel to Secret of NIMH. It would've worked better on its own if the pacing issues were fixed.
Short list first, this is spoiler-free:
The good:
I like that the movie has songs, I like songs
Timmy and Jenny both have nice personalities and voice actors, especially Hynden Walch as Jenny does a fantastic, cute job
Nice character designs. The other Brisby family members as teens/adults are interesting and cute designed
The general rescue mission would be nice
The bad:
The overall visual quality fits the usual "direct to video" quality. No painting-like backgrounds like in a Don Bluth or classical Disney movie, so, you can certainly see the lower budget, especially in character details (it's not ugly, though! Many characters are really cute.)
It severely lacks the emotion of the first one: no real gloomy sense of danger, no deep moments of hope
The pacing isn't good. The movie could've really needed the additional 30 minutes to reach usual 90 minute movie length: give them 10 more minutes to allow Timmy and Jenny to establish more of a relationship in Thorn Valley, give the rescue mission the other 20 minutes more
Oh god, what did they do to NIMH!? A professional human laboratory is now a scary, dark castle thing straight out of a Frankenstein movie!?
The antagonist, o god! Not WHO it is, but HOW it is displayed. Crazy and ridiculous instead of emotional and scary. THIS really is what doesn't fit any of the first movie's tone, it could very well be an episode of Chip 'n Dale Rescue Rangers where it would've been fitting more!
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Now some more details that include spoilers:
Technical aspects:
It's understandable that a direct-to-video release has a lower budget and, as much of a pity as it is, I expected that the backgrounds wouldn't have the painting-quality and style of the first movie.
But some other technical aspects are strange: some small scenes have very mediocre lip syncing, some short action scenes suddenly get really fast as if someone just pulled the film through the projector and in some scenes talking already start before characters are actually close enough to start talking, which adds to the general feeling of bad pacing as everything feels rushed.
The pacing:
The movie could've needed a longer run time. Especially when it comes to developing Timmy's and Jenny's relationship before switching it over to a romance.
The actual rescue mission would've also needed more time. More planning, clearer showing of the fire outbreak, smarter, more emotional fights against the antagonists.
Especially character relationships could've used the time.
NIMH and the evil plot:
Oh god, NIMH...
NIMH is supposed to be a clean, professional human laboratory. Of course it would feel like a jail and torture to the animals. But in this one, it becomes a creepy "castle" with wild experiments, crazy professors, strange Frankenstein-contraptions and stuff like that.
This would've fit in another movie, but not in a sequel that's supposed to depict the same NIMH the first movie had.
And in addition to that: talking, brain-washed monster-cats as henchmen!?
Again: This would fit in a mice-based adventure movie. But into the Secret of NIMH universe? No...no, not really
THE antagonist:
Okay, now, especially with how everything is established in the beginning, the antagonist itself isn't totally unfitting. There could've been legitimate reasons, it could've been explained perfectly fitting on an emotional level and it could've been solved on the same.
But instead they go a total "crazy scientist" way, totally unfitting of the character and more ridiculous and crazy than a serious movie like the first one should've gotten.
Many reviews say the film did Mrs Brisby bad. I actually think that her aging and not being important anymore is legit in the future, considering she's aging normally. (As much as I'd have loved to see more of her! <3)
But the antagonist...man, that one really got a bad development, which is a pity, as I said, from an emotional point of view, you could've done something with this.
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So, is this a horrible movie? I don't think "horrible". I liked how Thorn Valley was depicted, Timmy and Jenny are cute and lovely on their own and together.
I think outside of the NIMH universe and with better pacing, this movie would've had potential.
But like this it feels very rushed and undeserving of being called a sequel, sadly.
I still enjoy the general character designs, the songs and the good job the voice actors did!
I don't "like" the movie as it just isn't a good sequel.
But it's also not totally horrible. If you can keep it on your mind as an independent movie from the first one, enjoy some cute mice and songs.
Wasted potential, though, and that's really a pity, because the characters and the Thorn Valley setting could've been so much more!
