From its first few seconds, Rango, the computer-animated film starring the voice of Johnny Depp, asks the perennial question: what’s worse than a lonely lizard? The answer: a lonely lizard with an affinity for role-play and a severe personality disorder to boot.

He’s not quite Rango when the film opens. He is Lars, a scaly-skinned, pop-eyed, tropical red shirt wearing chameleon living in a glass terrarium. His fellow residents include a dead cockroach, a plastic fish decoration and the busted bust of a Barbie doll. Secluded from human (or reptile) company, Lars does what a normal lizard under these circumstances would do: he manufactures a play with his fellow in-animates as supporting characters.

Then in an instant his world is thrown out of a recklessly driven car and shatters on the Mojave speedway. Road-bound without a destination or a habitat, Lars is guided by an astute Quixote-like Armadillo (Alfred Molina) to a water-depraved town that’s home to a mix bag of creatures who don’t eat each other. Their two life threats come from shortage of water and a hawk.

Quite unexpectedly, the stranger with no name inherits the quality of most successful formulaic westerns: he becomes their hero-savior Rango — a name he picks up from a rum barrel, and completes it with a western drawl and a tall tale.

Depp, with the versatility of a professional voice actor balances John Logan’s vibrant, homage-bound screenplay about spaghetti westerns — a genre, seldom in vogue in recent history.

Apart from Depp, the other three big weights are the film’s glorious computer animation of not-really-photorealistic landscape and creatures (and a keenly colorful palette); the heatstroke-inducing ultra-realistic cinematography (consulted by the king of westerns, Roger Deakins); and Gore Verbinski, the director debuting in computer animation, from who we’ve seen the first trilogy of Pirates of the Caribbean, The Ring and The Mexican.

Rango’s humour, which comes in infrequent dollops, is a little too mature for its target audience — kids, pre-teen to teen; and the storytelling is a little too critic-friendly.

Written by John Logan and directed by Gore Verbinski, the film stars the voices of Johnny Depp, Isla Fisher, Abigail Breslin, Ned Beatty, Alfred Molina, Bill Nighy, Stephen Root, Harry Dean Stanton, Ray Winstone and Timothy Olyphant.

Presented by Nickelodeon and Paramount, Rango is rated PG. The big rattlesnake at the end will give kids a real scare.