ShadowDance

And there have been a lot of rumours. Rumours that the budget was double the stated amount, more like $500m. Rumours that the 3D effects were making people nauseous. Rumours that the film, two hours and 40 minutes long, was a complete car crash.

The Guardian can reveal that the last two are untrue. The film does not make you feel sick and it is not a disaster. All journalists watching the movie in Fox's Soho headquarters had to sign a form agreeing not to publish a review or even express a professional opinion online or in print before Monday.

So by saying Avatar was really much, much better than expected, that it looked amazing and that the story was gripping – if cheesy in many places – the Guardian is in technical breach of the agreement. It is not a breach, however, to report that other journalists leaving the screening were also positive: the terrible film that some had been anticipating had not materialised. It was good.

The King of the World sets his sights on creating another world entirely in “Avatar,” and it’s very much a place worth visiting. The most expensive and technically ambitious film ever made, James Cameron’s long-gestating epic pitting Earthly despoilers against a forest-dwelling alien race delivers unique spectacle, breathtaking sights, narrative excitement and an overarching anti-imperialist, back-to-nature theme that will play very well around the world, and yet is rather ironic coming from such a technology-driven picture. Twelve years after “Titanic,” which still stands as the all-time B.O. champ, Cameron delivers again with a film of universal appeal that just about everyone who ever goes to the movies will need to see.

Cameron reportedly wrote the story, if not the full script, for “Avatar” at least 15 years ago but decided he had to wait until visual effects capabilities advanced sufficiently to credibly render his imagined world and its inhabitants. On this fundamental level, the picture is a triumph; it’s all of a piece, in no way looking like a vague mish-mash of live-action, CGI backdrops, animation, performance capture and post-production effects. On top of that, the 3D is agreeably unemphatic, drawing the viewer into the action without calling attention to itself. The third dimension functions as an enhancement, not a raison d’etre, so the film will look perfectly fine without it…

On an experiential level, however, “Avatar” is all-enveloping and transporting, with Cameron & Co.’s years of R&D paying off with a film that, as his work has done before, raises the technical bar and throws down a challenge for the many other filmmakers toiling in the sci-fi/fantasy realm. The lead team from Weta in New Zealand as well as the numerous other visual-effects and animation firms involved have done marvelous and exacting work, a compliment that extends to every other craft and technical contribution on view.

The movie is 161 minutes and flies by in a rush. Repeat business? You bet. “Titanic”-level business? That level may never be reached again, but Fox will see more than enough grosses worldwide to cover its bet on Cameron.

But let’s cut to the chase: A fully believable, flesh-and-blood (albeit not human flesh and blood) romance is the beating heart of “Avatar.” Cameron has never made a movie just to show off visual pyrotechnics: Every bit of technology in “Avatar” serves the greater purpose of a deeply felt love story.

As with everything in “Avatar,” Cameron has coolly thought things through. With every visual tool he can muster, he takes viewers through the battle like a master tactician, demonstrating how every turn in the fight, every valiant death or cowardly act, changes its course. The screen is alive with more action and the soundtrack pops with more robust music than any dozen sci-fi shoot-’em-ups you care to mention…

In years of development and four years of production no detail in the pic is unimportant. Cameron’s collaborators excel beginning with the actors. Whether in human shape or as natives, they all bring terrific vitality to their roles.

Mauro Fiore’s cinematography is dazzling as it melts all the visual elements into a science-fiction whole. You believe in Pandora. Rick Carter and Robert Stromberg’s design brings Cameron’s screenplay to life with disarming ease.

James Horner’s score never intrudes but subtlety eggs the action on while the editing attributed to Cameron, Stephen Rivkin and John Refoua maintains a breathless pace that exhilarates rather than fatigues. Not a minute is wasted; there is no down time.

The only question is: How will Cameron ever top this?

Game-changing - yes. Spectacular - absolutely. Occasional dodgy dialogue and dramatic imperfections - of course. But still - wait for it… - a titanic achievement.

An epic film born entirely of Cameron’s imagination, Avatar uses tailor-made technology to create the most astonishing visual effects yet seen on screen and blends them seamlessly into a mythical sci-fi story.

"I haven't cried like that since Titanic."

most astonishing visual effects yet seen on screen

But one thing is certain: The real — and maybe only — loser here is Robert Zemeckis. His motion capture in A Christmas Carol looked only marginally less wax-mausoleum-awful when it first hit theaters than it did in The Polar Express. But now that Avatar is out, it's nothing but a rubbery antique.