Rating: *****

Verdict: Go see. Be amazed. More so in 3D.

Well, he's going to have to start working on another line.

"I'm the king of another world" might well do it when James Cameron hoists a further Oscar next year.

Because this Best Picture shoo-in certainly has the best picture - in 3D, it's an immersive wonderland that certainly feels like it's been beamed in from another planet. It's madly beautiful and vast and, while the look of the place might recall 70s prog-rock album covers or airbrushed panel van art, it's hard to dismiss it when you are flying through it.

That's Pandora, the moon of a gas giant orbiting Alpha Centauri, the nearest star to Earth. There, in the year 2154, we are the invaders wanting - as all aliens do - to make off with natural resources (a magic mineral called unobtanium) despite the objections of the primitive but plucky locals.

It's 15 years since Titanic ended with young Leo turning a possibly inspiring shade of blue and helping make Cameron's last feature the biggest movie of all time.

Since then, the director has been mucking about filming on the ocean floor - the inhabitants of which influence the fauna here - and waiting for the technology to catch up with his ideas for this epic.

The story though, is almost as old as movies themselves.

It's that one about a well-meaning colonial invader bonding with the natives to the point he switches sides.

Sure, this upgraded version has plenty of high-tech tweaks and it also borrows heavily from Cameron's great last space foray, Aliens, with its space-grunts, its scheming corporate guy, its robo-hardware, and the presence of Ripley herself, Sigourney Weaver. Though here, her feisty scientist Dr Grace Augustine is a closer relation to her Gorillas in the Mist character.

But, like Ripley was caught between the aliens and the guys from head office who wanted to weaponise the incubating creature; so, too, is Jake Sully (Sam Worthington), a paralysed ex-marine who has signed on for the Avatar programme which has his brain driving a super-athletic tall, Na'vi version of himself.

And, like the ship was the backdrop to its steerage-to-posh love story in Titanic; so, too, is Pandora with Sully finding his initially clumsy clone drawn to Neytiri (Zoe Saldana), a Na'vi princess who teaches him the way of the forest.

There, the beauty of the giant flora and the helicopter-bugs sure takes the edge off being worried by the resident nasties - panther-dogs, hammerhead hippos or the giant flying goannas, which will let you ride them only after they are broken in, just as Apaches used to tame their ponies in Westerns.

Yes, it's got a big, ecological thing. It also has allusions to 9/11 and the War on Terror and Vietnam.

Scenes discussing the war bits do suggest that the gravity is actually really strong on Pandora, with the lines making a loud clunking sound as they hit the floor.

But it also has a big, possibly blue, romantic heart at its core.

This helps make a movie with the greatest flying lizard versus helicopter gunship dogfight ever be much more than just outlandish space-war spectacle.

He's a true visionary, is Cameron. But he still has really bad taste in music.

The song by Leona Lewis - Celine Dion's alien clone surely? - over the end credits (which feature lots of folks from the various Wetas) is enough to shatter the need-to-see-it-again afterglow that Avatar induces. Almost.

Cast: Sam Worthington, Sigourney Weaver, Zoe Saldana

Director: James Cameron

Rating: M (battle violence)

Running time: 165 mins