Starring Martin Freeman, Ian McKellen, Andy Serkis • Directed by Peter Jackson • Age restriction: 13V   • Releases 12 December

First things first. This is not Lord of the Rings 2.0. If you're expecting the same level of epic-ness as Peter Jackson's adaptation of The Return of the King, you're likely to be disappointed. Just as The Hobbit was a lighter book – written by JRR Tolkien for children in 1937, 17 years before the publication of the first volume of The Lord of the Rings – so the film is more whimsical and fantastical than its Oscar-winning cousin.

Right, now that the warning has been passed on - on to our review.

Much has been made of Jackson's return to Middle-earth, 11 years after the big-screen release of The Fellowship of the Ring – and what a return it is. Visually astounding, rich in story and featuring some marvellous performances by actors both old and new – The Hobbit: An Unexpected Journey is a marvellous film, although not without its flaws.

In The Hobbit: An Unexpected Journey, we join unlikely hero Bilbo Baggins (Martin Freeman) at the start of his quest to the Lonely Mountain as the "burglar" for a company of dwarves, led by Thorin Oakenshield (Richard Armitage) who is hell-bent on reclaiming the lost dwarven kingdom of Erebor from the fearsome dragon Smaug. Accompanied by Gandalf the Grey (Ian McKellen), Bilbo and his companions face challenges including trolls, wargs, orcs – and the mysterious and tragic character of Gollum (Andy Serkis) – as they make their way across Middle-earth.

A hot topic in the weeks leading up to The Hobbit: An Unexpected Journey's release has been Jackson's decision to take the rather trim source novel and split it into not two, but three films. Of course, the film is not The Hobbit as you may remember it from your childhood reading of the novel – Jackson and his team of writers (including formerly-attached-to-direct Guillermo del Toro) have pulled a lot of material from various appendices to the original novel, meaning that there are more back-stories and a larger trove of characters. The film opens with an epic flashback to the loss of Erebor to the dragon Smaug, includes quirky and bizarre appearances by wizard Radagast the Brown (Sylvester McCoy) and an implication that we'll get to see what Gandalf gets up to in his disappearance to battle the Necromancer, as well as returning cameos by Elrond (Hugo Weaving), Galadriel (Cate Blanchett) and Saruman (Christopher Lee).

The who's who: A 'Hobbit' character gallery

The film's greatest flaw – although, for fans like me wanting to spend even more time in Middle-earth, hardly a fatal one – is the film's length. The film takes a while to get going: There's a lot of wandering around Bilbo's hobbit hole, awkward meetings with dwarves and a fair amount of singing. But once Thorin's company is out in the wilderness, the film picks up considerably – although this is probably only an hour in.

Yes, it is very long and very padded. And yes, Jackson has been completely self-indulgent. At two hours and 46 minutes long – for just the first film – it is clear that Jackson has been unable to cut very much from his script at all, and seems determined to hold on to as much material as possible. Whether this is a creative or financial decision will no doubt be debated until the cows come home – but this film could have been stripped down dramatically to up its pacing. Don't get me wrong, though – by the end of An Unexpected Journey I was quite keen to head straight into the next film – The Desolation of Smaug!

Jackson has done marvellously to tie The Hobbit films to The Lord of the Rings films. The opening appearance of Frodo (Elijah Wood, back in hobbit feet!) and old Bilbo (the wonderful Ian Holm) coincides with the party that opens The Fellowship of the Ring – and helps us feel right back at home in Middle-earth. Coupled with familiar strains of some of Howard Shore's Lord of the Rings score and the aforementioned return of Gandalf, Elrond, Galadriel, Gollum and Saruman, An Unexpected Journey feels at once familiar.

In Martin Freeman – who shines as the Watson to Benedict Cumberbatch's Holmes in BBC's Sherlock – Jackson has found himself an almost perfect Bilbo. It is as co-star Ian McKellen said during the early shooting of the film: Freeman is Bilbo. Slightly bumbling and awkward, hesitant and yet marvellously brave, Freeman only blossoms as the film goes on – becoming almost resplendent during the iconic "Riddles in the Dark" scene with a returning Andy Serkis as Gollum, who gave me goose-bumps and looks as though he never left behind the role of Smeagol that made him a household name during The Lord of the Rings. Also somebody who seems to have never left Middle-earth, Ian McKellen as Gandalf is a delight – bringing his usual energy, comforting tones and twinkle to the role of the grey wizard.

Sadly, out of a sizeable company of dwarves, only a handful are even noticeable. Richard Armitage is solid as the abrasive and doubting warrior king Thorin Oakenshield – if he is a little darker than his novel counterpart. Otherwise, out of the rest of the company only the young, good-looking ones (Fili and Kili) and the wizened Balin are given much screentime to shine.

Also worth a mention are the Goblin King (voiced by Barry Humphries) and new villain Azog – the Pale Orc that tracks the dwarves along their journey to Erebor, hellbent on claiming Thorin's head, and contributing to an increasingly menacing tone as the film nears its final climactic battle sequence.

And an obvious highlight of The Hobbit: An Unexpected Journey are the exquisite New Zealand landscapes and the impeccably detailed interior sets – with Bilbo's hobbit hole, Rivendell and the goblin cave shining in particular. The film has a very light, bright palette for much of the running time – forest greens, bright sunlight and flame – it echoes its often light and humorous tone, even though the film slips every now and then into a semi-pantomime feel.

While much has been made of Jackson's decision to film his new trilogy at 48 frames per second – twice the usual 24fps – I unfortunately didn't get to see the film in its new format. I can tell you, however, that the 3D was largely standard fare for a blockbuster film – although the CGI and create effects provided by Jackson's favourite Weta Workshop are superb as always.

A warning though: This film is a victim of its own hype, which is at the moment positively immense. Although it is flawed, An Unexpected Journey provided a welcome, entertaining return to Middle-earth. The latter half of the film more than made up for a slow start, and I relish the next visit in December 2013's The Desolation of Smaug.

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