Damn you John Constantine. Damn you to Hell. Oh, someone already has. Keanu 'woah' Reeves is currently struggling to make himself heard over theOneliner.com 'Another Fecking Comic Book Adaptation' klaxon, shouting that he's delighted to embody the lead character of the Hellblaser comic of which we know very slightly more than absolutely nothing about. Apparently the fanboys are up in arms about the 'reimagining' of Johnny Boy as, well, Keanu Reeves rather than the acerbic Liverpudlian they've come to know and love. Let's ignore this slender band of naysayers and plunge into what we could possibly get away with calling the first blockbuster attempt of the year.

John Constantine hunts demons. It's that simple. While angels and demons certainly exist in the Constantine universe, they're supposed to keep their noses out of human affairs, although whispering in ears to provide gentle nudges in either direction seems encouraged. Often demons break these rules of engagement, and often Johnny has to send them back to Hades with extreme prejudice. He's not entirely doing this out of the goodness of his heart, prior sins currently putting his own soul on the express elevator to hell come checkout time. With his current evil-banishing day job he's hoping to restore enough karmic balance to bribe Saint Peter into opening the pearly gates for him before the 30-a-day cigarette induced lung cancer sweeping through his, er, lungs claims his life.

He's helped in his offbeat profession by some equally offbeat characters, Beeman (Max Baker) fulfilling the Q role of demon slaying weapon dispenser and Father Hennessy (Pruitt Taylor Vince) fulfilling the, er, fat priest role. John even has a sidekick in Chas (Shia LaBeouf), largely kept to driving duties. While this sounds dangerously like it's turning into some awful ensemble evilfighting mess, these guys are used in such sparing quantities that the title of the movie was never going to mislead - this is very much about Constantine. He notices he's been working harder of late, more demons taking more risks. Something big is afoot, it would seem.

Angela Dodson (Rachel Weisz) doesn't care about demons, she's a cop. She does care about her sister Isabel, who's dead. Apparently taking her own life after getting out of the looney bin, this doesn't sit right with Angela's opinion of Isabel's character. In the course of her digging she coincidentally stumbles across Constantine's path a few times, until it becomes apparent both their fates are linked to an insidious plot to bring the son of Satan into this plane of existence. This, for those unsure of the concept would be a Very Bad Thing, so John decides to stop it aided only by his crucifix shotgun. Don't ask.

It's actually harder than expected to pin down exactly what Constantine is trying to be. Thankfully the trailer's implication of being The Matrix Revelations isn't reflective of the work as a whole. It's sort of an action film, what with the all the demon blasting and such going on in the final reels. It's sort of a horror film, seeing as it's difficult to slot exorcisms into any other category. Repossessed excepted, natch. You can't really ignore the writer's opinions on religion, which are thankfully shuffled off to the background rather than have the movie stop to discourse theologic dogma, a worthwhile discussion but not one that belongs in glossy big budget Hollywood unit shifters. Time and a place, my friend, time and a place.

Constantine winds up being a somewhat uneasy mix of the lot of them, which alternates between working well and falling over almost scene by scene. I want to say that it doesn't work because of the more ludicrous leanings it takes to religion and the supposed war between heaven and hell. I would feel slightly silly saying that, because I was happy enough to accept the premise that the world is really a computer simulation and we're all really stored in vats somewhere during The Matrix. With that kept in mind, Constantine doesn't work because of the more ludicrous leanings it takes to religion, although your mileage may vary.

However, it certainly has its moments. Fashionable as it is to knock Reeves' ability, he gives a memorable and accomplished performance of the cynical slayer. I'd feared he'd wind up as Neo in a dog-collar, but he does a script that on occasion oozes sarcasm proud. And of course he gets to smoke and look cool, balanced only by the hacking fits where blood is coughed up. Remember kids, winners don't do drugs. He embodies a strange consistency of internal logic and external appearance very well, so it doesn't feel too odd that we can laugh at some pretty bizarre images (such as Constantine sitting in a basin of water grimly clutching a cat) without denigrating the movie's ethos too badly.

Rachel Weisz does alright in a role which is ultimately thankless, accent aside, and the supporting cast do similarly alright. Nothing much worthy of exceptional praise, but nothing poor enough to be singled out. Very average indeed, although Peter Stormare makes an interesting choice of Satan and Tilda Swinton makes a borderline bizarre choice of Archangel Gabriel. Djimon Hounsou shows up in a role that for once isn't Imposing Native Guide #1, for which we are thankful, although if anyone knows what we did wrong to be subjected to Gavin "Eejit from Bush" Rossdale we'd appreciate being let in on it.

The effects are reasonable, and the depictions of Hell suitably, er, Hellish. It's a very adequate and competent bit of filmmaking, but the attempts to have it appeal to as mass a market as possible seems to have taken the edges off it. It's a very calculated production to ensure no-one's left feeling gypped, but by the same token it's difficult to imagine anyone taking this to their hearts as a favourite film. It's somewhat neutered, for want of a better term, but we're starting to sound as cynical as Constantine now. I've no real complaints to level at this film, but no real reason to be excited by it either.

Were I in the business of passing quantifiable judgements, I'd award this 3/5 TippyMarks.