The original Avatar hoodwinked us all. Like every other critic and casual reviewer I drew parallels with The Blair Witch Project, The Jazz Singer, The Wizard of Oz and the Lumiere brothers' 1896 short Arrival of a Train at La Ciotat – movies that signified major shifts in technology, ushering in new eras of colour, sound, cinematic language and marketing.

Even though 3D wasn't new, Cameron showed its entire 20th century history how to do it, and the world building that went into Pandora was so eye popping we thought we were witnessing a new epoch.

A decade and a half later, 3D turned out to be Hollywood's latest con job and it's already all-but extinct once more (they handed us 3D glasses when I saw Avatar: The Way of Water and it wasn't even projected in 3D).

And even though the motion capture and animation that went into creating Avatar's world was a quantum leap forward back in 2009, every year sees improvements on movie technology and all this time later you might remember how amazed you were seeing that CGI, but does anybody ever remember the graphics themselves, other than how immersive they were?

As cinema proves to us time and time again, the only thing that ensures longevity is the characters and the story. As a Generation Xer, I can't count the number of movies from the 70s and 80s I still love where you can see how badly they've aged when you watch them with 30-plus years of hindsight.

And as I confirmed to myself the second time I watched Avatar in its entirety recently, the characters and story were the weakest part of the movie. We saw all those cheap jokes about Dances With Wolves and Ferngully at the time for good reason.

All of which is was a way of saying that I went into Avatar: The Way of Water with very low expectations. Even though the technology that went into filming motion capture underwater was no doubt transformative and incredible – James Cameron would never accept anything less – I was sure it was going to be just another blockbuster rather than a quantum leap forward, and I wasn't disappointed.

The premise is still something you could write on the back of a postage stamp. In fact, just like nobody seemed to realise about Terminator 2: Judgement Day at the time, Avatar: The Way of Water is virtually a remake of the original film.

After the Na'vi won the war against the humans keen to exploit Pandora's natural resources, the humans are coming back to start a new war with the Na'vi and exploit Pandora's natural resources.

The only difference here is that Jake Sully (Sam Worthington), having been transplanted permanently into the body of his Na'vi avatar and now the leader of the tribe, realises that staying with his people will put them in danger.

So he takes his wife Neytiri (Zoe Saldana) and their clutch of teen and pre-teen kids and flees to ask another Na'vi tribe who lives beside the ocean whether he can hide his family there.

While they try to fit in, the human forces led by the new incantation of Quaritch (Stephen Lang) – his uploaded consciousness taken before he died in the first movie downloaded into a Na'vi body to give him superior strength and skills – are hunting Jake down to take revenge.

After following the domestic dramas at their new home and taking its sweet time introducing us to new ecosystems of creatures and life forms, Quaritch is of course going to find Jake and the fight will be on all over again.

There are lots of familial and narrative twists and turns in the three-plus hours that carry you to the climactic smackdown. Sigourney Weaver's character from the first film had been reborn in the guise of Kiri, one of Jake and Neytiri's adopted children who can still contact her own former presence in Pandora's spirit network but suffers an epileptic fit from the experience.

Another is the human child Spider, who was left behind when the humans retreated and has grown up as a Na'vi and will prompt the most cack handed 'who do I belong to' subplot you've seen in years.

Then there are their two biological sons, who – together with Kiri and Spider - interact with the ocean clan kids in a bunch of scenes that made me feeling like I was watching an American high school drama with all its narrative threads about the new kids not fitting in, being bullied by the tough kids, having to make friends, rebelling against parents and getting into trouble, etc.

We might not have seen CGI on a par with what Cameron achieved even in the original Avatar after all this time because he was so exacting and demanded such high quality, but that doesn't mean you don't forget the graphics very quickly.

In one way that's a compliment to the film because every scene looks like it really was photographed on (and underwater on) an alien planet depicting these amazing creatures. But when you settle into the suspension of disbelief so effectively and completely there better be something else there – especially during three hours of runtime – and there just isn't.

I was reminded of what George Lucas did with his cinematic universe after the original Star Wars, demoting himself to building, populating and writing (the first draft) but leaving the directing to a far better talent.

The parallels doesn't strictly apply here because Cameron is in fact one of the best directors working. But there's no more writing talent in this film than there was first time around – ironically so, considering he had a really good writing team in Rick Jaffa and Amanda Silver, who did such great work in the most recent Planet of the Apes series.

If you're invested or just caught up in the colour and movement, the flaws might not bother you, but Cameron doesn't just repeat them all here form the first movie, he repeats them over and over again.

I remember a very insightful and funny article talking about one of the Disney-era Star Wars films where the writer was referencing how many characters let out a loud 'woohoo' every time they fly a spaceship, and how every time it happens the audience feels the exact opposite.

I thought of that every time someone jumped on the back of one of those flying animals (or the flying fish things the ocean people ride). The camera wheels and dives through the air or water after them and the characters whoop with delight the way the movie wants the audience to, and it ends up demanding a level of enjoyment that just isn't earned.

But that's not all that comes off as ridiculous. Jaffa talked in an interview about the fact that one of the Sully kids could talk to the giant cetacean creatures that are so important to the story, and what a risk it was because it would just come across as stupid unless they got it right.

It's stupid. With the kid standing on the fin of the huge creature – staring straight into its pervy, peering eyeball – he says something to it in the Na'vi language complete with onscreen subtitles, and when the whale thing emits a series of rumbles and whalesong, it's likewise translated on screen into English.

Yes, you're indeed watching a talking whale.

Beyond that, they've spent hundreds of millions of dollars on this whole enterprise and they still couldn't get human piece of gyprock Sam Worthington a bit of dialogue coaching, his accent veering between American and Australian not just within a scene but sometimes individual sentences.

And in what might have been a final pisstake nobody noticed, the centrepiece of the climactic battle is another sinking ship – in a James Cameron movie. Suddenly it's Titanic II!

Avatar was such a phenomenon it was nominated for Best Picture, like Star Wars back in its day. That's what happens when movies become such powerful pop culture moments in the world.

Years later, the only awards The Way of Water will collect will be in the technical categories – just like Star Wars. It's another example of just how the wool has been lifted from our eyes and how a cinematic universe so big we all thought was going to end poverty and cure cancer has ended up just another mildly entertaining sci-fi jam.