Dr. Seuss hasn’t fared very well with film adaptations. Sure, the television specials made from his books have been winners. But the features? “How the Grinch Stole Christmas” was tolerable, but “The Cat in the Hat” was so execrable that it wasn’t even good enough for the litter box. “Horton Hears a Who!” is an improvement on both, first of all because it’s animated rather than live-action. But it still isn’t the gem one might have hoped.

First of all, because the CGI animation—of the computer-generated variety—has much of the plastic look one encounters on children’s TV. The Whoville sequences are atmospheric and Seussian, but the scenes in Horton’s jungle home, while pleasant enough (especially when he gets to the clover field—not Manhattan’s, of course) are nice but nothing special. One might have wished for more imagination here.

Then there are the voices. Steve Carell makes a fine mayor, and Seth Rogen is amusingly deadpan as a mouse named Morton who’s Horton’s pal. And Charles Osgood, from the CBS Sunday morning magazine program, is the perfect narrator, catching Seuss’ singsong verse beautifully and sounding like everybody’s favorite uncle. But Jim Carrey works awfully hard as Horton, and his manic intensity seems at odds with the character’s nature. Will Arnett, by contrast, manages to damp down his usually overbearing act as Vlad the eagle. But while Carol Burnett might have seemed a great choice for the sourpuss Kangaroo, her voice is just too recognizable, and her tone too shrill.

Still, miscalculations in the voices pale beside some in the storytelling department. The original, of course, is a pretty slim and simple tale, which barely provided enough material for a half-hour television special. So Cinco Paul and Ken Daurio have had to beef up the narrative to justify a feature. Sometimes their contrivances work—the expansion of background on the mayor’s home life, and the transformation of Jo-Jo into his quiet little son and heir (in a house with an army of daughters) is an inspired touch. The change in the Kangaroo’s son (“pouch-schooled,” in one of the script’s wittier inventions) into a kid uncertain of his mother’s rigidity and, finally, the decisive voice among the animals is nice, too. And some of the added secondary characters have spunk.

But elsewhere the additions are designed to turn Seuss’ whimsical original into something more blustery and conventional. There’s a scene of Horton crossing a rickety suspension bridge, for example, that’s all too reminiscent of the empty action stuff that fills kiddie movies nowadays. And the assault on Horton by the Kangaroo and the Wickershams is jacked up into a huge lynch-mob extravaganza that breaks the mood. In Whoville, meanwhile, there’s a very peculiar plot twist that has the mayor treated as a crackpot by the snooty town councilors. It’s obviously intended as a parallel to the disbelief Horton faces in the “real” world, but it takes a weird turn when the “democratic” government is dismissed as ineffectual and disposable when compared to an “inspired” individual—you might even says it’s kind of an argument for dictatorship.

And then there’s the big finale, in which the little Whos make enough noise for the jungle animals finally to hear them. In the story it’s a pretty simple process, here turned into something much more slam-bang and extravagant. Apart from the wisdom (or folly) of encouraging the children in the theatre (and, soon, at home in front of the family entertainment center) to make as much noise as possible—after all, they may well treat the invitation as a Tinker Bell audience-participation moment—one has to wonder just why Jo-Jo’s been building that huge drum machine in the abandoned tower, anyway. Viewers today expect a flashy close, to be sure, but in this instance something a bit less raucous might have been welcome.

Still, one can’t be too hard on “Dr. Seuss’ Horton Hears a Who!” Yes, it blows up what’s essentially a sweet little fable into something far bigger and louder, but while it lacks enchantment it retains just enough of the original’s charm to make good family fare.