I can't speak to a novel I haven't read, but what quickly comes across in watching this film is that at least compared to other contemporary titles, and filmmaker René Laloux's other works, it's rather distinctly primed for a younger audience. By no means is this to say that it's inherently any less worthy, but in centering a preteen child as a major character, and including two non-human creatures who speak and behave with a childlike mentality, there's little mistaking the more family-friendly slant. More substantively, enjoyable and engrossing as the story is, it arguably feels a bit more simplified as one sometimes anticipates of features tailored to a younger audience - or at least, it seems that way as it's better about communicating big ideas in the narrative rather than all details that should theoretically round out that narrative and enrich it. To that end, the result feels marginally incomplete, as though we're seeing a jigsaw puzzle that's been assembled but with a scattered few pieces missing. Even so 'Les maîtres du temps' is much more enjoyable than not, and pretty good if one happens to come across it.
There's no rule that says every picture has to be a perfect, grabbing masterpiece; sometimes it's enough for one to suitably serve its purpose. I think that's rather the case here as I'm glad I took the time to watch, but I just don't feel like I'd ever been inclined to watch again. If a tad deficient the plot is nevertheless modestly compelling, with great ideas providing firm foundation like cairns on a snow-covered hiking trail. Meanwhile, though active animation elements (characters and creatures) may not be as richly detailed as we've seen elsewhere (including even in Laloux's later film 'Gandahar'), the designs thereof are nonetheless splendid. Above all, the painted backgrounds that fill our vision at any given time are a real joy, and surely the chief highlight of the movie overall. Structures and landscapes are a veritable dreamscape of far-out visuals that boast a level of texture and careful complexity that's otherwise not always present in the title, and no small amount of the value here stems just from the illustrators' work. Kudos all around!
I did have a good time watching, and whether one is specifically a fan of someone involved, the genre, animation at large, or just looking for something to fill eighty minutes, I think 'Les maîtres du temps' earns a fair recommendation. It's not necessarily something one needs to go out of their way to see, but despite its weaker points I think the feature is fine just as it is. If you have the opportunity to watch, this is worth checking out.