The full-length animated feature Karas: The Prophecy (released 24th April) has been hailed as "Batman with a samurai sword," and features impressive visuals around a plot that's not so easy to grasp. I'd have to agree with the "Batman" comment – Karas's setting is gloomy enough to be Gotham City, and our black-clad hero's vigilante ethic is much the same as the caped crusader's. But whether the story is as good as it sounds is another matter entirely.

Karas is set in a depressing, perpetually-stormy version of Shinjuku, where youka (demons) exist alongside humans, in the shadows, where no-one can see them. But just like humans, youkai get ill too, and their "doctor" is Otoha. By day, he dishes out medicine to sick demons – by night, he transforms into the menacing figure of Karas, the youkai's chief protector against anything that might do them harm.

Lurking in the background is Eko (Matthew Lillard; Scooby-Doo), an ex-Karas, who's become disillusioned with the youkai's peaceful coexistance with humans, and wishes to stir things up a little. He employs an army of cybernetic youkai called the Mikura, and his goal is to capture all the youkai in the world and turn them to his cause. Otoha – with his mentor Yurine (Piper Perabo; Cheaper By The Dozen) – is tasked with stopping Eko's plans and saving the world.

During the course of the story, we meet several smaller players who've become caught up in Eko and Otoha's conflict: the X Files-esque detectives Kure and Sagisaka; odd-jobs girl Hinaru, and enigmatic Mikura-fighter Nue (Jay Hernandez; Hostel).

There are several problems with Karas's narrative structure, not least of which is that this is Part 1 of 2 – the second part, Karas: The Revelation, follows later in the year. You would think that because of this, Karas would have ample time to flesh out all of its characters, main and supporting – which brings us to the second problem: it doesn't get around to it. Karas sacrifices character development for flashy CGI-based action scenes (which I'll talk about later), leaving the characters as little more than pawns in a narrative that's dragged in far too many directions to be truly cohesive.

The third problem with Karas is the plot itself – it's almost completely incomprehensible. Most of the plot synopsis above didn't come from my understanding of the feature; instead, I had to rely on what I was told in the promotional material. In fact, when I first started watching Karas, I saw the first half-hour of it, got bored and switched it off. It took me a while to muster up the enthusiasm to finish it off so that I could review it. The feature simply doesn't explain anything about the plot or the characters – the viewer is expected to magically "know" what's going on before he even tunes in. This is not a good storytelling technique; it's barely tolerable in productions based on books or comics, and just bad form in original productions like Karas.

For all its sins, Karas does know how to do a good battle scene. Every battle in the feature is presented in full CGI, and it looks amazing. Rendered mostly in matte-black tones and thus maintaining a silhouetted effect, Karas transforms effortlessly between ninja, car and flight modes and clashes with well-designed Mikura monsters – ranging from a vehicular monstrosity to an alluring spider-creature. I must applaud the animation team; this is the most technically-accomplished CGI production I've seen since Star Wars: Episode 3. Karas's fighting style seems to borrow from Super Sentai, with its "cool" poses and signature maneuvers, but mixes in some of the cinematic magical techniques common to Japanese console RPGs (such as the Final Fantasy series).

On the voicework side of things, Manga's decision to cast three "big name" Hollywood actors – if you feel comfortable calling Hernandez, Lillard and Perabo "big" – strikes me as a ittle pointless. It bothered me in Princess Mononoke, and it bothers me here. Hernandez comes across as the best of the three, but Lillard is underused and Perabo is totally wasted on the emotionless character of Yurine. I respect that this is a very high-profile release for Manga, and that they obviously wanted to draw in mainstream sci-fi/action fans as well as the usual animé/manga crowd, but they would've done a lot better to have veteran English voice-actors playing the roles instead.

As for music, Karas again reminds me of Final Fantasy; there's a particular "ominous" theme used at least twice that I'll swear blind has been ripped from Nobuo Uematsu's scores. The main battle theme features pumped foreign chanting, a la Matrix impresario Don Davis. And as always, there's a J-Pop ballad over the ending credits, which is about as generic as you can get.

To sum up, Karas is the ultimate triumph of style over substance. The CGI battle sequences blew me away, but the plot isn't explained in sufficient-enough detail, and none of the characters have any depths beyond basic personality type and motives. Hopefully, the second part of Karas will bind the story and characters together and go some way towards explaining why viewers looking for a well-told story would have any pressing need to watch this.

The 1.85:1 anamorphic picture here is first rate. Colours are strong and detail is very good – the slightly overexposed look in some sequences is deliverate and proving common in recent animé releases.

The Dolby 2.0 stero mix is a good, but the 5.1 and DTS tracks are really impressive, with sound coming at you from every direction in the battle scenes and some thumping bass in the music and effects. The rears are sometimes very specifically used, and at one point had me looking over my shoulder at noises I thought, just for a second, were taking place in the room.

As befitting its high-profile release, Manga has stuffed Karas full of extras – the best of which isn't a true "DVD extra", but a micro-comic included in the packaging. This comic – produced by Dark Horse in a western, not manga, style – explains a little about the plot of the feature, and chronicles Otoha's first meeting with Eko. As a fan of western comics myself, I found this offering to be very welcome indeed.

On the first disc, the special features are: a Behind the Scenes look at the feature's Japanese production (3:40); wireframe-to-CGI Concept Animation comparison shots (2:34); interviews with Japanese Voice-Actors; and sound effects (20:00) – which, bizarrely, is the longest and most detailed feature of the lot. Finally, there's the original Japanese trailers and TV spots for Karas.

Disc 2 takes the Ghost in the Shell turn of including the DTS audio track for the main feature, and no extras other than Manga Entertainment's usual bevy of trailers. In order: the Art of Animé promo; Ghost in the Shell 2, Ghost in the Shell SAC 2nd Gig, Millennium Actress, Street Fighter Alpha Generations, Tetsujin 28, Submarine 707R, Tokyo Underground, Heat Guy J and Survive Style 5+.