All else being equal, it's tremendously gratifying to encounter an animated film - and a nominally family-friendly one, at that - which is so resolutely personal as Rango; even if one does not adore or even like it, there's absolutely no arguing that it comes from the same mentality of test-marketing and formula and commercial calculation as most American animation does right now. It is self-evidently a labor of love, and more than that, a profoundly weird labor of love that's equally as far from DreamWorks' reliance on contemporary references and sarcasm as from Pixar's emotionally-searing comic chases. A cultural grab-bag that both parodies and homages the spaghetti Westerns of the '60s and '70s (much as Blazing Saddles was at once parody and homage to the classic Western of the '50s), Rango is the kind of film where hardly one image or line seems plugged in because some studio executive thought it would "sell"; instead, it feels like every last idea is there because director and co-scenarist Gore Verbinski and his team of animators and filmmakers had some urgent want that it should be there. Little or nothing feels calculated about Rango, which admittedly gives the film a certain shaggy, sloppy character; yet it is also the main reason the film is so exhilarating and alive.

The plot is pure Western boilerplate, done with talking animals: a chameleon in a Hawaiian shirt, voiced by Johnny Depp, ends up stranded in the Mojave Desert for reasons not really worth recounting; his attempt to survive the scorching desert sun first takes him to a mystic armadillo (Alfred Molina) who sends him to the town of Dirt, where water is the primary medium of trade and desert creatures of every sort fill in the customary roles of a frontier community: the ancient, calculating mayor, a turtle (Ned Beatty), a tart-tongued young female lizard named Beans (Isla Fisher), fighting to keep her late father's ranch, the pragmatic doctor, a rabbit (Stephen Root), and so on. The chameleon gives himself the name "Rango", taking his cues from the first handy object with writing on it, and becomes sheriff of Dirt when he makes up some exploits to fill his backstory. He then rouses the townsfolk to fight for their way of life in the face of adversity and drought.

It's staggeringly familiar from a vast number of Westerns, and the second half begins piling on details from Chinatown at a brisk clip; the heart and soul of Rango lies not in its narrative, nor in the hero's progression from lonely, anonymous lizard to beloved hero (a most undernourished thread that is, I think, mostly present as a fig leaf to convince the moneymen that this is a messagey kids' movie). This is a movie all about the details jammed into every corner of the film: copious references to its genre (a creaking windmill out of Once Upon a Time in the West, a title uncommonly similar to the seminal Django), only slightly less-copious references to cinema at large. And then the things that aren't references at all: the depiction of Rango as a neurotic and quite possibly insane character at certain points, especially in the early going; the warped anti-logic with which Western tropes are bent into corkscrew shapes to fit the film's idiosyncratic world (a rattlesnake, voiced by Bill Nighy, with a six-shooter tail!), and character designs that are, I won't quite say "ugly", because that's not right at all. But one peek at the semi-ubiquitous Rango trailer is all it takes to observe that the strange combination of hyper-realism and caricature that went in to the characters is most certainly not appealing in the way of most contemporary animation - look no further than How to Train Your Dragon, a film with similarly stylised characters and reptiles that are in some ways angular and graphic, yet would make perfect stuffed toys, and then try to figure out what fucked-up little child would want to cuddle a stuffed Rango doll.

The dominant mode of the film, that is to say, is absurdity, and better than absurdity: a kind of rarefied, unashamed silliness. It's not only Depp's performance, reminiscent of his work in Fear and Loathing in Las Vegas without simply repeating it, that recalls the work of Terry Gilliam: the whole film has a similar anything-goes sensibility to his Monty Python animations, with perhaps less anarchy. But the collage of notions and gags unbound by anything other than the filmmakers' own fascinations, that is here in spades.

It's nothing so much as a candy bowl: eye-popping colors here, stunningly-rendered bleak desert vistas in bleached-out shades of white there (all-star DP Roger Deakins consulted on the artificial cinematography, and the end result unmistakably recalls his work on No Country for Old Men; and arguably even more, his work on Fargo, with sand instead of snow) - it's the first animated film produced by visual effects powerhouse Industrial Light and Magic, and their industry-defining attention to detail and love of craft is practically touchable in this film. Hans Zimmer's best score in quite a long time blasts out on the soundtrack, a patchwork quilt of inspirations and outright thievery that doesn't so much result in a quintessential Western musical landscape as the jazzed-up Pez candy version of the same. Visually and aurally, it's a film all made of odds and ends, the perfect accompaniment to a string of gags ranging from bargain-basement slapstick to bone-dry black comedy, in the space of five or ten seconds, all of it anchored by Depp's best performance since the first time he teamed with Verbinski in Pirates of the Caribbean: The Curse of the Black Pearl: a hectic onslaught of accents and emotional registers and line readings that wrap around themselves in spirals, always devoted to the best interests of the film and its comedy.

By and large, all of those odds and ends are pitched at a very particular target: adult cinephiles who'll get the references and who are very willing to undergo the grown-up version of down a whole pack of Pixy Stix all in one go. Rango is way the hell out there; it's fatiguingly long; and it is not for kids, despite a PG rating. Oh, the funny talking lizard is kid-friendly and all, but the mentality, in all its obsession, is pitched way over their heads. And that, more than anything, is what makes Rango a treasure: it wasn't made for real kids or theoretical market driven kids, or for me, or for you. It was made, I suspect, for Gore Verbinski, working out all his manic energy on the screen. It's that singularity of vision and personality that always makes the most interesting films, and Rango has firmly staked a claim to being, at the very least, one of the most wholly unique movies of 2011.