The least that can be said is that the direct-to-video sequels are consistent. While Don Bluth's original film of 1988 is a minor modern classic with welcome earnestness (however much we may scrutinize it), after Universal Cartoon Studios took over the property, each title in turn has been distinctly lesser. They're still modestly enjoyable, but the shortcomings are evident, and they're built for uncomplicated entertainment and flavor more than sincere storytelling and substance even as solid story ideas and themes may be broached. Notably, this fifth entry is marked by the most significant changes in personnel - in its cast, and even more in its crew - since the first sequel of 1994; would that have any impact on the outcome? It should come as little surprise that for better and for worse the answer is "no," and 'The mysterious island' fits right in with its kin. Scarcely any sooner than it begins one can recognize the same tenor, and how much one can get on board with it will depend on how much one can abide something that says "frivolous Saturday morning cartoon" more than "heartfelt full-length feature."
So we again see a movie that boasts many admirable qualities, but which has been reduced and simplified to a more unsophisticated rendition. There is splendid detail and vibrant color in the visuals, including active elements and even more so the painted backgrounds, but the visuals are also robbed of some nuance, and occasionally there's strange, unnatural and stilted movement. The voice cast is great in and of themselves, including icons like Jeff Bennett and Rob Paulsen, but they seem to have been guided into performances that are extra cutesy and childish. The original score doesn't specifically stand out yet is lovely nonetheless; at the same time, the original songs are unfailingly gauche, some being better and some being worse. And while there are indeed honest and meaningful notions in the screenplay, the dialogue, revised characterizations, scene writing, and overall narrative are decidedly more straightforward and uninvolved, catering directly to the very youngest of viewers and declining the complexity and thoughtfulness that would help the material to appeal to broader audiences and stand the test of time.
There's mild humor to go along with the mild adventure and mild drama, and we even see the return of a supporting character for the first time in a few years. Just as some tidbits are weaker, some are stronger, and even quite clever. The sum total is, in fact, light fun that's suitable for a quiet day. One just wishes that the continuing saga of Littlefoot, Cera, Ducky, Petrie, and Spike were treated more mindfully, with a smidgen more of the intelligence and refinement that would make for an honest, engaging viewing experience for viewers older than pre-schoolers. I like 'The mysterious island' well enough as it is, but I also won't think on it at all hereafter, and there's the rub.