Roald Dahl's writing for children has only a moderate record of reaching the screen with its naughtiness intact - a pair of not-bad stabs at Charlie and the Chocolate Factory, a middling Matilda and Nicolas Roeg's paralysingly scary take on The Witches are among near-successes to date. Wes Anderson's film of Fantastic Mr Fox continues the trend of being diverting but never substantial enough to register as more than a doodle in the margins of Dahl's book.
It was a slim yarn to start with - a wily, chicken-snatching fox outwits the three farmers who are trying to flush him and his kin from their den. The new characters and backstories added to Fantastic Mr Fox by Anderson and his co-writer, Noah Baumbach, don't make it any meatier, though they do bring the film rigidly in line with their previous films about eccentric American families. Anderson's works include The Royal Tenenbaums and The Darjeeling Limited; Baumbach directed The Squid and the Whale. The pair have the "melanchomedy" market sewn up, and Fantastic Mr Fox has been reimagined in that image; it feels less like an adaptation than a benign takeover.
The film comes up trumps, however, in its vivid autumnal colour scheme and its delicately rendered stop-motion animation. The animal puppets were made using real fur, which shifts restlessly from frame to frame (my daughter said it looked like the characters were standing under hairdryers) and has a prickly quality in close-up. The glassy eyeballs occasionally incorporate some cartoonish shorthand - an asterisk replaces the pupil to indicate unconsciousness, while death is signified by a cross. Those eyes never blink, not even when they're moist with tears. The effect suggests a taxidermist's workshop sprung to life.
Against this feral background, the Fox family's urbanity is gently amusing. Mrs Fox (voiced by Meryl Streep) is the warm and wise linchpin of the family, a painter specialising in brooding landscapes bisected by streaks of white lightning. (When the den is destroyed, a farmer holds one of her itsy-bitsy canvases between his chubby fingers; it's a lovely, Lilliputian moment.) Mr Fox (George Clooney) is a newspaper columnist who gave up thieving before the birth of his son, Ash (Jason Schwartzman), but now finds the old urges, otherwise known as instinct, stirring in him. The cleverest scene exploits an internal tension between nature and civilisation that is ignored by most animated films. Mr Fox wonders idly whether anyone reads his column, then snips it carefully out of that morning's paper at the breakfast table, before diving snout-first into a stack of toast, snarling gruesomely as crumbs and crusts fly.
It's a plum gag, as well as a way for the film to have its toast and eat it by acknowledging another layer of reality beneath the debonair foxes and badgers who've passed the Bar. Perhaps it's a sign of Anderson's inexperience in the genre that he sometimes misjudges the anthropomorphic divide. It's hard to say why a fox writing columns or wearing a bandit's mask is funny and right, while an opossum that flashes a credit card and boasts of paying its bills on time is not, except that fantasy is a fragile construct and a detail that's even slightly off can make everything wobble. By the same token, the tiniest gag of a suitable hue can light up a scene; Charles M Schulz himself would surely have chuckled at the briefly glimpsed label on a beagle's rabies medication: "Take with meat. Do not operate heavy machinery."
Audiences new to Anderson's work will be able to savour his trademark style, which is characterised by pedantic detail, snappy montages, symmetrical framing and more cross-sections than a geology textbook. For the rest of us, the picture provides further evidence that Anderson desperately needs to leave his comfort zone. Once again, he gives the same character types the same conundrums to work through - from the patriarch whose adorable wildness prevents him from being a dependable parent, to the strong mother with a colourful past who is nevertheless excluded from playing much part in the action. If Fantastic Mr Fox feels like Anderson's freshest film since Rushmore, that can only be due to the animation. Beneath those tactile textures, there's nothing you could strictly call fantastic.