Dir: Roberto Rodriguez. US 2003. 101 mins.

You have to give Roberto Rodriguez his due: he's nothing if not ambitious. Take the title of his new film. With a dose of homage and a dose of parody and a slug of bare-faced presumption, Once Upon A Time In Mexico declares its desire to occupy the same place in Roberto Rodriguez' oeuvre as Once Upon A Time In The West did in Sergio Leone's. That masterpiece was a compendium of all the tricks known to the godfather of the Spaghetti Western. This, the third and final episode in the Mariachi trilogy, is less the masterpiece, and more of an enjoyable staging post in the mad onward gallop of Rodriguez' Taco Western fantasy world.

The trilogy was never originally meant to be a trilogy: it was only on the set of Desperado - the follow-up to Rodriguez' enfant-prodige debut, El Mariachi - that his friend and collaborator Quentin Tarantino suggested to the Texan director that he should make it three. Shooting in Mexico wrapped over two years ago; the delay since then must have more than a little to do with US distributor Sony's nervousness about the public's appetite for the shoot-em-up ketchup movie in these pious times.

They needn't have worried. Rodriguez' appetite for twisted baddies and creative killing seems, if anything, to have increased with the years; but the violence is served up with such tongue-in-cheek gusto that only the most humourless moralist would take offence. And although the budget of this one is several factors larger than the $7,000 which the director famously shelled out for El Mariachi, it was still tight enough to give the effects that home-made edge that first turned us on to the exploits of the reluctant, guitar-toting hitman. The cast may be starry this time, but the producers economised elsewhere: by shooting on high-definition digital, by imposing a seven-week production schedule, and by Rodriguez' decision to cover all the main technical bases, as a glance at the credits reveals.

Once Upon A Time's plot can be confusing, especially during the flashbacks that show Antonio Banderas (El Mariachi) and his knife-throwing partner Salma Hayek (Carolina) in happier times. The main premise - the attempt by Johnny Depp's morally ambiguous CIA agent to sabotage a drug cartel's plan to overthrow the Mexican president - is simply a peg on which to hang a spectacular series of action sequences. The best of these first has Hayek and Banderas swinging their way down the facade of a hotel, linked by the wrists via a long chain, then segues into a trailbike chase that ends in an oil-tanker explosion. Rodriguez does this sort of stuff like an old woodcarver making an ornate cabinet: the pleasure is in the craftsmanship.

Depp hams it up for all he's worth (this seems to be his main mode these days), especially towards the end, when the make-up department contrives to make him look like a cross between Alex from A Clockwork Orange and Edward Scissorhands. The director's colour-soaked photography brings out that Mexican spirit at least as well as Frida. And there are plenty of cultural in-jokes, from El Mariachi's Matrix-like mobile phone appeal 'I need a new line - this one's been compromised' to Depp's solemnly delivered 'I am living the Vida Loca'. Ironic and referential enough to appeal to even the most hardened cineaste, Once Upon A Time In The West can also be taken at face value as a tequilla-tinged modern cowboy yarn. It should reach out to those that missed the first two parts of the trilogy - something that the self-contained storyline has clearly been designed to facilitate.

Prod co: Troublemaker Studios
Co prod: Dimension Films
Int'l sales: Miramax
Prod: Elizabeth Avellan
Co-prod: Carlos Gallardo, Roberto Rodriguez.
Scr, Cinematography, Prod des, Ed, Music: Roberto Rodriguez
Main cast: Antonio Banderas, Salma Hayek, Johnny Depp, Mickey Rourke, Eva Mendes, Danny Trejo, Enrique Iglesias, Marco Leonardi, Cheech Marin, Ruben Blades, Willem Dafoe.