There are some novels that you know would make great films but that you also know will never, paradoxically, be made into great films. These are stories that would take so much money to visually realise that they would be impossibly compromised by the artistically corrupting force of star power and the Hollywood Machine. Of course, a good part of what makes these novels such great works is the way they are written, something that is virtually impossible to translate into cinema. That's not to say that the right director cannot find a suitably cinematic equivalent – I can think of plenty of examples of great films from great books where both works have their unique appeal. But there are plenty of times I'd be happy for the film-makers to just leave the book alone and instead take influence from it, admit to the borrowing of ideas but take them down a their own cinematic path.

One such novel is William Gibson's seminal 1984 science fiction work Neuromancer. As dense a read as you'll find in modern sf literature, it's crammed to the gills with astonishing ideas, visual ideas, the sort of thing that modern, CG-driven film-making should theoretically thrive on. But despite a string or abortive attempts, the film version has never appeared, and despite my initial excitement at seeing Gibson's words translated into imagery, I couldn't help but breathe a small sigh of relief. After all, look what happened when Hollywood took on one of his short stories. Johnny Mnemonic happened. It had star power (Keannu Reeves), it had the big Hollywood budget, it even had potential cult status in the casting of Kitano Takeshi as the bad guy. And yet it stank. It is now principally remembered as the film whose completion was marked by the near-fatal motorcycle accident that almost ended Kitano's career.

And yet the ideas within Neuromancer, its vision of a dark, decayed industrial future in which man and machine are becoming increasingly intertwined. and where the virtual world is globally connected via 'cyberspace' and 'the matrix' – terminology coined here for the first time in this context – have permeated any number of subsequent works of literature and film, and even society itself ('cyberspace' is now a commonly used term for the internet and has even entered the Oxford English Dictionary). The film world actually had the jump on the cyberpunk movement with Blade Runner, which pre-dated Gibson's novel by two years, and even Tron's vision of a physical cyberspace is in the Neuromancer ball park. Cinematic cyberpunk otherwise remained largely on the fringes, at least until 1999 when it went global with The Matrix. But in the end it was not Hollywood that most effectively embraced many of the novel's most intriguing concepts, but Japanese anime, and specifically Oshii Mamoru's 1995 Kôkaku kidôtai, or as it was known in the west, Ghost in the Shell.

Based on the manga by Msamune Shrow, Ghost in the Shell was, like Ôtomo Katsuhiro's Akira before it, a rare thing in anime, a film that single-handedly expanded the genre's fan base. Set in 2029 in a world in which networking is far more than just a business term, the story revolves around Section 9, an elite undercover security force formed to combat the activities of sophisticated hackers and cyber-criminals. The Section's most skilled and powerful operative is Major Motoko Kusanagi, whose cybernetic body carries only the brain of the original human she once was and what is referred to as her 'ghost', the essence of her original self or her soul, if you will. Her long-standing friend and occasional partner is Batou, a cybernetically enhanced operative of almost equal skill and commitment, while the mission around which the film revolved saw them trying to track down and destroy a particularly skilled hacker known as 'The Puppet Master'.

Almost as dense in its plotting and texturing as Neuromancer itself, Ghost in the Shell demonstrated that the anime feature could be as complex and intelligent as even the smartest live action film and a good deal of science fiction literature. As striking for its design and animation as for its plotting and characters, the film managed a near-perfect mix of action, narrative, technology and philosophy that was targeted squarely at adult audiences – this was NOT one to take your kids to. The film developed a serious fan base and to this day is rightly regarded as one of the key works of both anime and science fiction cinema.

News that a sequel was on the way generated considerable excitement within the realms of anime fandom, but the frustration factor of having to wait almost two years after the film's Japanese release for the film to reach UK screens no doubt prompted an awful lot of internet downloads. I was fortunate enough to see it in the first month of its release in Tokyo, and on my return to the UK the mere mention that I'd done so prompted the most unexpected people to suddenly turn their heads, widen their eyes and ask urgently, "You've seen it?!" Yes, it generated that level of anticipation. When the fans finally got to see the film they'd been so anxiously waiting for, reaction was a little mixed, something I also experienced at that first screening in Japan. But the passing of time seems to have changed all that, and the film's reputation has been steadily climbing. Personally, I never had any doubts, as from my first viewing – without the aid of English subtitles I should add – I knew I had witnessed something that was every bit as special and spellbinding as the original.

The year is now 2032 and Batou is cybernetically enhanced to such a degree that only his mind remains as it once was, one haunted by the memory of his vanished ex-partner, Major Motoko. Now teamed with the younger, largely human Togusa, he is called in to investigate the case in which a Gynoid – a realistic female robot created specifically for sexual companionship – has malfunctioned and slaughtered its owner. The case turns out to be far more complex than it first seems, bringing the pair into conflict with everyone from violent Yakuza gangs to powerful hackers, and Batou towards a meeting with an old friend and colleague...

Although Ghost in the Shell 2: Innocence shares much with its predecessor, it is in as many ways a starkly different film, something hinted at on the original Japanese release, where the posters did not include the Ghost in the Shell prefix and the film played simply as Innocence. That said, I would still recommend anyone who has not already done so to see the original before approaching this sequel – even genre fans have had trouble deciphering some aspects of its almost dream-like narrative, and you'll need more than the supplied textual prologue to really understand what is going on with the characters, especially Bataou, who has been moved here to centre stage.

There are inevitable comparisons to be made with Blade Runner, from which Innocence borrows plot points and imagery, something that Oshii freely admits to – he goes as far as suggesting that all films set in the future are now influenced by it. Oshii even borrows from his own previous work, recreating a memorable scene from the live action Avalon (widely considered to also be part of the Ghost in the Shell universe) in which the lead character simply prepares food for his dog, a basset hound glimpsed only briefly in the first film that seems to have become something of an Oshii signature, and one of the film's key symbols of the innocence of the title.

But in all other respects Innocence is as strikingly original as its predecessor, perhaps even more so. The pace is slowed, but that in no way dilutes the density of ideas or the complexity of the narrative. There has been a clear move away from action towards philosophy, as the two Section 9 operatives move through the investigation and ponder on both the nature of their prey and of humanity itself, something that those living in this futuristic society appear to have completely lost touch with. When the action does come, as in the battle with the heavily armed Yakuza gang, it is staged with considerable aplomb, but is always integrated into the story in ways that sometimes only become clear after the event. In one of the film's most extraordinary scenes, Batou walks into a convenience store to buy dog food, only to hear Motoko's voice tell him "You've stepped into a killing zone," and a simple shopping trip turns into a hunt-the-killer game with the store's occupants, as Batou surveys every corner with Terminator-like visual enhancement. The scene ends with the suggestion that it is now Batou who has malfunctioned, but in a time in which people are able to bio-mechanically connect to the Network via their e-brains, a skilled hacker is able to gain control not just of your computer, but your very self.

Elsewhere the action takes on a more unsettling aspect, exemplified by an opening sequence in which Batou hunts out the damaged remains of a Gynoid that has killed two policemen. Dressed and made up like a Geisha, she is the very picture of delicate womanhood until she tries unsuccessfully to kill Batou, then tears open her chest to reveal her biomechanical interior, pleading for his help as she does so. Is this a malfunction or is she under some sort of external control? And why would a robot plead for help? Has it become self-aware? Is it pleading for its existence or to have hers terminated? Batou obliges the latter. Later, he does battle with a seemingly never-ending army of such mechanoids, mechanical representations of innocence that are slaughtered where they stand. Yes, there's plenty of metaphorical meat to chew on here.

Clear explanations are in short supply and even hardened fans have been left scratching their heads at some aspects. At one point we appear to be caught in a Run Lola Run-style replaying of events, each of which differs slightly from the one before and that only provide an answer to a problem when the experiences are compared and combined. If, indeed, they were experiences at all.

Visually the film is a stunner, the integration of cell-drawn animation with computer-drawn 3D backgrounds providing a consistently gorgeous feast for the eyes, with the CGI work never feeling incongruous or in any way superficial. It has to be said that the film's considerable visual impact is severely diminished on the small screen – sequences that made my jaw drop in the cinema have more of an "Oh that's nice" quality about them on DVD, lacking the sheer scale and level of detail that only a cinema-sized screen and a 35mm film print can deliver, although the inventiveness and poetry of the design and the sometimes beautiful character animation still leave you agog. The soundtrack is similarly crucial to the film's other-worldly atmosphere and qualifies as a sometimes hypnotic art piece, with Kawai Kenji's mesmerising score once again providing the film with its musical heart. There are moments – in particular an extraordinary street parade involving giant mannequins, festival floats and animals – that seem to have been staged almost solely for their audio-visual beauty, but they never feel out of place, adding to the sense of shifting reality and waking dream that dominates the second half.

There's no doubt that Ghost in the Shell 2: Innocence is not for everyone, and even some anime fans, those who like their action loud and their plots straightforward, are going to struggle here. There is a feeling of melancholy that runs throughout, a sense of sadness for a future in which humanity is increasingly being surrendered to machinery of our own creation, making the film feel as much Philip K. Dick as William Gibson. One thing's for sure, despite its influences, it's still primarily and uniquely Oshii Mamoru, and if you surrender to his distinctive style and approach then you're in for a cinematic experience quite unlike any other. It is a bold and visionary work of remarkable beauty and fierce intelligence, and though it may play just occasionally like a drugged out evening with two world-weary philosophy majors, it's still one hell of a trip.

In common with other Manga DVDs of late, Innocence impresses in its picture quality, and in terms of detail fares better than most, something not obvious in the cell drawn sequences, which have a slight softness that is deliberate (especially in the final scene). The CGI material, however, is close to pristine, with the festival parade and the opening title sequence in particular looking terrific. Colour reproduction is strong throughout, and the transfer copes well with the film's varying use of light levels, from the saturated whites of the crime lab to the shadowy darkness of alleyways and night-time streets. The picture is framed 1.85:1 and is anamorphically enhanced.

There are three soundtrack options (well, that's not strictly true, as all three are available both in the original Japanese and with a new English dub, which technically makes it six) – Dolby 2.0 stereo, Dolby 5.1 surround and DTS surround. Although the stereo track is fine, the 5.1 and DTS tracks are far superior, with the DTS just having the edge in breadth and clarity – both have impressive separation and make subtle and atmospheric use of the rears and the LFE channel. Kenji Kawai's score sounds terrific throughout.

The English dub, or should I say American English dub, is very much a matter of taste, but once again I found it seriously inferior to the original Japanese. Technically there is nothing wrong with it, but performance-wise it leaves quite a bit to be desired, consistently lacking the low key subtlety of the Japanese track, the dialogue and delivery sounding too often like a dodgily acted 40s detective story. This is hardly surprising when you consider that Oshii was not involved in this dub in any way, and it can thus be argued, as with any such track, that if you watch the dubbed version you are not watching the film that Oshii created, but someone else's version of it – it's not just about what is said, but HOW the lines are delivered. But even if you allow for that, the dub here wanders from the original script. While the subtitles represent a reasonably accurate translation of the Japanese dialogue, the dub is a localised interpretation, Americanising the language and, more problematically, making subtle and at times significant changes to the wording. For example, "I have requested a data link" on the Japanese version becomes "They're asking me for a data link" on the dub; "It delayed our investigation" is changed to "That's why you didn't get promoted"; and "The brain must have been taken to sell on the black market" mutates into "Pro-active firewalls must have zapped him hacking in somewhere." You pays your money...

One thing I should mention is that, like Manga's recent Ghost in the Shell: Stand Alone Complex DVDs, the 2 disc set here actually contains two copies of the film in exactly the same cut, but the version on disc 1 has the stereo and 5.1 tracks, while disc 2 has the DTS. Quite why they have taken this approach is uncertain – the film's length makes it unlikely that disc space was at a premium, though the bitrate is consistently high. Most of all, though, it makes for slightly deceptive advertising – when you buy a two disk set you expect the second disc to consist primarily of extra features, which in this case it clearly does not.

There are two extras on disc 1.

The Making of Ghost in the Shell 2: Innocence (16:00) looks very much like a Japanese EPK for the film (although one made after its entry in Cannes), but is interesting nonetheless, not least for providing a look at the faces behind the character voices. There are interviews with Oshii, composer Kawai Kenji and several of the animators, plus footage of them at work and some rough drafts of the animation, all of which is interesting stuff for anyone interested in the film or the process of animation in general.

Unusually for an anime feature, there is a Commentary with director Oshii Mamoru and unit director Nishikibo Toshihiko, conducted in Japanese with optional English subtitles. Inevitably, there is quite a bit of discussion of the technical aspects of the design and animation, but they also talk about the development of character and story, as well as the thinking behind key scenes. A consistently jovial and engaging chat, the two praise crew members for elements they are happy with, but still criticise things they'd like to have changed or which were hard work to realise. The scene with Batou and his basset hound prompts some of the most entertaining banter. The two have plenty to say – there's not a single dead patch here.

On the second disk we have SAC 2nd Gig Sneak Peak (5:01), which is a pop-video commercial for the second series of the TV spin-off, Ghost in the Shell: Stand Alone Complex, plus a scattering of extracts. Only the English dub is available on this one.

Far more interesting is a Face to Face Interview (23:44) with director Oshii Mamoru, who kicks of by admitting that he doesn't mind foreign language dubs of his films, but that this does result in a different film from the one he made. I have no doubt that was asked this up front by Manga in the hope of countering moans about the English dubs. Sorry, but I'm sticking to my complaints. He also suggests that no future-set film made nowadays can be free from the influence of Blade Runner, which he deeply admires, and talks about the popularity of anime in the west, the differences between the two Ghost in the Shell films, the importance of the relationship between humans and pets (his dog Gabriel was the model for Batou's own pooch), and whether it really is possible any more to create a film that can truly be considered original.

The Full Length Japanese Trailer (5:31) is exactly that, and without the aid of English subtitles. Cut to the Kimiko Itou sung Follow Me, heard over the film's closing credits, it captures the tone and pace of the film rather well, and is a rather seductive piece.

Also included are Trailers for five other Manga releases.

It may not work for everyone, but for me it just keeps getting better with every viewing – it's got to the point where I was watching the Japanese trailer (see above) and going glassy-eyed every time a favourite scene or shot came on. Although the narrative clarifies with successive viewings, there is still plenty that remains deliciously enigmatic and open to personal interpretation, and as an audio-visual experience it is, frankly, without peer, but is never emptily so – this is style with substance, and then some.

Manga's DVD delivers on sound and picture, and to a degree extra features, but don't be fooled by the 2-disk status, as the main special feature is, well, the film itself. Not that this should put you off – Ghost in the Shell 2: Innocence is anime for adults at its gorgeous best, and comes enthusiastically recommended.