The premise is irresistible: 85 minutes of quality time in the company of the Heath Robinson Jay and Silent Bob, the chance to see the world’s most famous claymation characters vaulting through the hoops of a real movie plot, and the name Peter Sallis above the title of a Hollywood studio picture. So it’s disappointing to report that Wallace and Gromit in The Curse of the Were-Rabbit, while doing almost everything that you’d expect, is somehow not quite up to scratch. It ticks all the boxes, but it hardly ever surprises you. You leave with the dull feeling that you got no more and no less than you paid for.

The premise, for anyone who’s been living as a hermit for the last fifteen years, is simple. Wallace, a bald bachelor of uncertain middle age, lives in a non-specific Northern English town with his faithful silent hound Gromit. Wallace has two great loves, cheese and inventions—hence the first of their adventures, A Grand Day Out (1989). Wallace, running low on Wensleydale, knocks together a rocket in his basement, and takes Gromit on a day-trip to the moon, which does indeed turn out to be made of cheese. The story itself was minimal, but it swept the viewer along through the sheer charm of its execution.

Watching the two subsequent short films, The Wrong Trousers (1993), and A Close Shave (1995), you have the sense that each time round the makers upped the ante. The Wrong Trousers not only looks technically miles ahead of its predecessor, but has an idea-a-second chase finale that leaves you gasping in amazement. A Close Shave, in turn, has a more complex and interesting story, with Wallace’s window-cleaning business leading him to The Wrong Woman, Wendolene, for whom he falls badly. But Wendolene’s glamorous wool-shop conceals a dark family secret: a cyborg dog running a covert sheep-rustling operation.

The first thing to say about Were-Rabbit—as I probably have to call it if I’m not going to spend half my wordage repeating the title—is that its plot, mood, and denouement are far too, uh, close to A Close Shave. Once again, a Wallace scheme (in this case "Pesto," a rabbit-control business to protect the town’s vegetables) leads him to meet another Wrong Woman—Lady Campanula Tottington, the local bit of posh, whose lawn is riddled with bunnies. (Of course she’s played by Helena Bonham-Carter. Did you need to ask?) Lady Campanula is being courted by the caddish Victor Quartermaine (Ralph Fiennes, in a performance that will stop you ever being able to see The English Patient without giggling.) Victor’s dog, like Wendolene’s in A Close Shave, takes an instant dislike to Gromit. Meanwhile, a monster is roaming the streets, munching the town’s vegetables, and our heroes (principally Gromit) have to track it down and despatch it. But where A Close Shave was close enough visually to The Terminator (1984) that you suspected James Cameron’s lawyers were napping that day, Were-Rabbit is stuffed full of images that, uh, closely reference the Emmerich/Devlin Godzilla (1997). That’s fine: this late in the day, films are made out of other films, and Park’s parodies-with-love work even if you’ve not seen the original. The challenge, as Ezra Pound said, is to make it new, and the newness of the first three films is just not present here.

The central problem is with the script. It’s partly that it’s not as funny as it thinks it is, and that jokes are flagged so glaringly that parents will be drumming their fingers—and heaven knows what their infinitely cannier nine-year-olds will be doing. This is a film, for instance, that actually includes the following exchange between a vicar and a pensioner as a laugh-line: "I have a hunch this’ll be a night to remember." "I just have a hunch." More generally, the script blatantly telegraphs where it’s going: as soon as you’re told that Wallace and his neighbours are growing their carrots for the annual vegetable show held at Lady Campanula’s home, you can tell exactly where the climax will take place. In particular, the last ten minutes, an overextended kinetic finale with Gromit in an airplane fighting off a more aggressive rival dog, are a direct rip-off of A Close Shave. Structurally, there’s at least one unexpected twist—the true identity of the were-rabbit—but this isn’t enough to stop it feeling like a thirty-minute film pumped full of air till it reaches an hour and a half. It’s certainly not an advance beyond its predecessors in wit or thrills.

It also, I think, oddly fails to play to the strengths of the Wallace and Gromit mythos. The central joke of Wallace and Gromit was that Wallace’s inventions were always much more trouble than they were worth—just like claymation. We felt affection for Wallace and his vastly overcomplicated, very English creations in the same way that we did for Nick Park and his crew, slaving away for months to produce a few minutes of footage. (Francis Spufford's book The Backroom Boys is a lovely chronicle of the boffin in British culture, and some future anthropologist will have great fun linking it with Wallace.) Wallace’s inventions are oddly underused here, and we only really get two: a bunny vacuum-cleaner which he uses to clear Lady Campanula’s lawn, and a mind-exchanger which drives the plot. One always sensed that there was a whole world of deranged botch-jobs sitting in Wallace’s TARDIS-like workspace, and the greater span of a movie should have been the perfect chance to explore that. But perhaps it’s too much to ask a single film to make storyable the mystery of what English men get up to in their sheds.

But at least the film hasn’t lost the charm of its predecessors, or headed off towards Hollywood plotting. Unlike almost any other studio picture you could name, the protagonist learns nothing, and experiences not a whit of personal growth as a result of the story. Nor do Wallace and Gromit’s adventures change the world: its flavour is utterly distinctive and utterly locked down, like the early Discworld books. Unarguably, much of that distinctiveness comes from the animation. The characters have a very specific vocabulary for expressing emotion—one shared with Park’s other work, Creature Comforts—which would be over-fussy if it wasn’t so recognisable. Fingers rustle busily, ears twitch, faces speak when the mouth doesn’t. (That’s why the characters have such disproportionately big hands, eyes, and mouths: these are the tools Park uses to tell the story.) The single finest thing about every one of the films, for instance, is Gromit’s eyebrow, a nubbin of plasticine conveying a huge range of emotion. Whether he’s doing shock, suspicion, or Sancho Panza resignation, he’s the most human creature on the screen. You could make a CGI movie from the same script in a quarter of the time, and doubtless get plenty of money from it, but it wouldn’t be the same. The physicality of the characters, the sense that they have weight and occupy space is something that CGI has still not accomplished.

Nor has a CGI film yet managed to convey the sense that everything is there because a human being has intended it to be. In a claymation world, everything in the frame can mean something, can be controlled and made to sing. So we get daft book titles on shelves, shameless overacting by background characters, a thousand little visual gems that you’d have to watch and rewatch to catch. And, as I say, there is the precious sense that this is an Eden that never changes, a Neverland like a childhood that you can always go back to. Wallace is forever a bachelor, and will remain so unless a Pratchett-like intelligence decides that he’s going to grow older, as Discworld has started to. The film is a let-down, and one that curiously fails to take advantage of the big screen, but still a joy. You won’t regret it if you wait for the DVD.

Graham Sleight lives in London, U.K., and writes for The New York Review of Science Fiction, Foundation, and Interzone.