Based on Hiroya Oku's popular manga, Gantz is a strange choice for a (relatively) big-budget Japanese live-action theatrical adaptation. The manga, after all, is famous mostly for how incredibly over-the-top it is in terms of violence, nudity, and the tendency to present humanity as being pretty reprehensible – how could even the hardest R rating contain Oku's pitch-black adults-only story? Based on Shinsuke Satō's movie, the answer is simple: rip Gantz's cynical, nasty soul right out and leave only the story's shadow in place.

That's not to say there isn't anything to like about this version of the story. It's a competently-made film, to be sure; well-directed, especially during the film's many explosive action sequences, with more-than-adequate CG helping things along. There are plenty of solid practical effects, particularly during the “game” involving the Green Onion Alien, where there are several homage shots to classic 80's slasher movies. Most of Oku's visually inventive ideas – the skin-tight leather super suits, the meticulously designed alien weapons – translate to the screen very well in three dimensions. For an audience that's totally unfamiliar with the original story, Gantz will probably feel like a mid-range sci-fi action flick with a weird Twilight Zone-style premise, albeit one with some big unanswered questions and stock, shallow characters that never get fleshed out. Something you'd catch on late night cable and say “eh, not bad, I guess”.

But for anyone who's even moderately familiar with Oku's original work, there's something very wrong here, right out of the gate. Kishimoto's entrance – naked and dripping wet from the bathtub where she slit her wrists – is chaste, a handful of PG-13 shots; that yakuza leers at her a little and then she's covered up by Kato's jacket. A shallow observation, to be sure – but isn't this the Gantz movie? This is the character who spends probably a third of her time onscreen naked or in some form of undress in both the manga and the anime and is literally referred to crassly by every other scumbag in the story (and the Gantz ball itself) as simply “Tits”? Absolutely it's shallow to point out the total lack of nudity, but this is an early warning sign that this adaptation has been thoroughly scrubbed.

That suspicion becomes even clearer as they develop the characters with what little time they have. It's totally understandable to condense the story – even 2 feature-length movies couldn't cover every plot point in the series – but what they decided to remove are most of the scenes that establish the three lead characters as tragic figures with difficult pasts, struggling to fit back in to a world they've already been removed from once. We get one-liner hints at the backstories of Kei, Kato and Kishimoto, a scene or two here and there with Kato's brother – just enough to establish who they are but not nearly enough to make us care or sympathize. It's not as if the ill-fated love story between Kato and Kishimoto ever really gets off the ground in the manga, but here it's barely a footnote; in fact, there are so many lingering shots of Kei and Kato smiling at eachother across the room and being relieved to see one another that there's more romantic tension between those two than any other couple in the story. Hell, they even took out Sakuraoka, Kei's short-lived love interest in the original story, the woman he has ridiculous monkey sex with simply because she's willing and he's pissed off and jealous that Kishimoto only has eyes for Kato. Instead we get a new love interest for Kei, an oh-so-adorable girl with an oversized scarf in his class who follows him around and draws him as a manga hero. They have a cute little conversation in a cute little sun-drenched café. It's a miracle she doesn't look right into the camera and point at her dimples.

In fact, the real problem with this adaptation can most easily be summed up by Kei himself. For fans of the manga and the anime, it isn't an exaggeration to say that Kei Kurono is not in the Gantz movie. The Kei Kurono fans know is a cynical, judgmental horndog – he's an asshole. His emotional journey from selfish, creepy jerk to somewhat redeemable leader who sees the value in the lives of others and cares about his friends is at the very center of what gives the Gantz story any real sense of redemption. But that isn't in here at all – the closest Kei gets to being even a little bit of a dick is when he starts getting cocky about his alien-killing skills. That's about as dark as they were willing to go with that character.  Otherwise he's a perfectly normal, somewhat awkward Japanese college kid. We don't even get the nasty little internal comments he makes about the people around him at the train station. And really, what's missing from Kei is what's missing in this film altogether.

Most stories – the ones that resonate with us, at least – have a “heart”, something that makes them what they are, for better or worse. Gantz's “heart” was pitch-black; it was gritty, cynical, unpleasant, and not at all afraid to stock up on scummy characters who show us the worst humanity has to offer. It was salacious and rough, sneering, the kind of thing you read when you're alone, something that puts you in a dark place mentally for a little while afterward. That isn't here. That's what's been removed. What's left of the characters after they decided to scrap all those scenes where we get to really know them are barely two-dimensional, fodder for an action movie with a high body count. That would be fine if this weren't an adaptation of a story that did have solid characters, that did challenge you with how dark it is, that did go places thematically that few stories go. The only vice it has left is violence – which is certainly represented here, with buckets of corn syrup blood splashed about during the games. But in the most important sense of what made Gantz what it is, on that level, it's been thoroughly declawed.

It doesn't help that the theatrical presentation of this film is dubbed in English. By and large, dubbing anything live-action in English has been abandoned as an outdated method. It never works, it's distracting, and oftentimes the dub performances are awkward, stilted, or just flat-out bad, sapping any sincere drama from the performances. The English-language performances here are all of those things, in some cases painfully staggered to match mouth movement, often making dramatic scenes unintentionally funny. While it's assumed the eventual DVD/Bluray of this film will include the original Japanese language audio track, it is a baffling mystery why they chose to dub this for the theatrical release, and it only hurt the film. Here's hoping the sequel will be presented in Japanese with English subtitles.

As a basic, mostly unremarkable sci-fi action flick, Gantz doesn't fail. It's a slick-looking, technically well-made picture that rises above the lacking production values that smear so many other anime and manga adaptations. Unfortunately, what it does fail at is being true to the spirit of the original story, and for fans of the original, it's a disappointment and a missed opportunity.