To a greater extent than most games, Heavy Rain is a story-driven adventure. As this is the case, the following review is devoid of plot spoilers, aside from character descriptions and a brief overview of the plot setup.

How far would you go to save someone you love? That's the question posed by Heavy Rain's tagline, but when it comes to discussing the game itself, it might be more useful to ask: "how willing are you to try something different?" Heavy Rain is many things: it's a slick little thriller, a work of interactive art, and undoubtedly one of the gaming experiences of 2010, but one thing it's not is familiar. It's a genuine departure from the status quo, and if you're the kind of hardcore gamer who thrives on shooters and little else, you may find it hard to get your head around.

For the sake of space, I'm not going to spend much time discussing exactly what Heavy Rain is. If you're totally new to the concept of this game you'd probably do well to check out one of our previous previews, but the gist of it is that you get to play through roughly 10 hours worth of "interactive fiction" - a term coined by the project's overseer, David Cage. Rather than using levels, or any other conventional video game structure, Heavy Rain unfolds its story over the course of 50 individual scenes. At any given time you'll control one of four characters, all of whom are looking for The Origami Killer - a child murderer who abducts his young victims and drowns them in rain water. Hunting for psychopaths isn't the safest of occupations, but if one of the protagonists should happen to die in the course of the investigations, the story will carry on anyway. There are no Game Over screens here, just a sinister narrative that grinds on to a conclusion - regardless of player death(s).

This highly unusual format, coupled with the game's astonishingly beautiful graphics, has attracted a lot of attention and dribbling hype from gamers and members of the press alike. This isn't "just" another PS3 exclusive; it's a balls-out attempt, on the part of developer Quantic Dream, to do something genuinely original with the medium. Sony has taken a big risk by backing this project, and everyone knows it. Personally, I've been eagerly awaiting Heavy Rain ever since I first heard about it, but after my last hands-on test the faintest shadow of doubt had crept into my mind. Yes, it was beautiful, and yes it was both provocative and highly original, but I also had a slight sense of being kept on a leash, of being forced along a relatively set path. Given all the noise that Cage had previously made about player choice, this seemed to be a potentially game-ruining disappointment.

Well, having played and finished the final product several times, I'm delighted to report that Heavy Rain is a roaring, highly emotive success. The preview code I was playing last time was limited to the first three hours or so, and to be honest these opening chapters are something of a slow start. However, as soon as the basic plot is established the action kicks up a gear, and from this point onward the pace barely falters. As per my promise at the top of the page, I'm not going to mention anything that even vaguely resembles a spoiler, but let's just say that the story is absolutely packed with surprises and stand-out moments - the kind of events that you'll instantly want to rant about. For the past few days my colleagues have had to listen to all manner of excited screams and caterwauls from the room next to the office, and every time they've attempted to investigate the noise I've nearly decapitated them by slamming the door shut.

The games uses 24-style split screens, but it does so sparingly.

There's been a lot of discussion around Heavy Rain's control system, and particular its reliance upon quick time events, but this arrangement is ultimately one of things that allows the game to be fresh and unpredictable. As a general rule you use the left analogue stick to steer your virtual actor about while using the face buttons and simple movements of the right stick to interact with the game world, following subtle on-screen prompts that appear over objects in your vicinity. Critics might argue that this imprecise setup effectively weakens the link between the player's input and the character's actions on screen, but after half an hour's worth of play it starts to feel like second nature. More importantly, it means that Cage and Quantic Dream can throw almost anything at you they like: rather than being a rigid system for governing, say, you're running and gunning (as per any shooter under the sun), the controls in Heavy Rain are a virtual Swiss army knife that allow you to deal with anything and everything.

Take a hypothetical situation in which your unarmed character is being chased by a man with a gun. You might typically start with a sort of "on-rails" bit where you're running away; during this interlude you might have to hit a series of sudden button prompts to let you evade obstacles in your path, and you might get a split second choice of routes to take: up a set of stairs, or into an open doorway. You opt for the room, and after barricading the door, you're suddenly returned to full player control. You've got a limited amount of time to act: you could run over to the window and try to open it; you can dash to the phone on a nearby desk and call for help; or you could try to hide inside a cupboard. The first two choices would probably require simple, one-off actions, while the latter would force you to press and hold a series of buttons in sequence, simultaneously. This kind of challenge frequently crops up throughout Heavy Rain, usually during highly stressful moments, and it ultimately resembles a kind of hand-held version of Twister. The hardest of these tests will leave you with both hands contorted into a painful knot, mirroring the struggle of your on-screen counterpart. It sounds a bit daft, but it works extremely well.

This is Norman Jayden. He's now one of my all-time favourite videogame characters. You'll love him.

While these flexible controls are the key to the game's wide-ranging action set pieces, it's the virtual cast that make them count. Alongside Uncharted 2, Heavy Rain sets a new standard for lifelike human characters, and while the game generally employs a highly stylistic look, there are times where you could be forgiven for thinking that you're watching a film or high-budget TV show. The effect isn't constant, naturally, and the occasional odd movement or strange expression will remind you that you're playing a game, but the fact remains that these are characters who feel alive. You can read their mood from their expressions, from the way they move, and you'll soon realise that you actually care about what happens to them. Aside from the child actors and a few minor characters who are a bit too colourful for their own good, the cast turn in some very strong performances.

As you might expect, the central quartet are particularly well-drawn and voiced. Top honours should probably go to Leon Ockenden as Norman Jayden, a drug-addicted FBI agent who comes across as a good man haunted by his demons, but Sam Douglas also does a great job as Scott Shelby, an avuncular private detective whose inherent good nature steers him through all manner of tough spots. I found that it took me a little longer to warm to the other two characters - architect Ethan Mars and journalist Madison Paige. Mars is actually the star of the show, but he's about as far removed as you can get from your typical video game frontman: He's depressed, mentally confused, and more than a little tragic. I initially found the experience of "playing" him to be a bit jarring, but you're probably supposed to feel that way - and he ends up going through so much for the sake of his missing kid, it's hard not to empathise.

It feels a little strange to be writing such things in a game review, but the characters really are the heart of Heavy Rain. The atmosphere conjured by the constant drizzling rain, the bleak-but-beautiful lighting and the sublime music definitely plays an important role too, but it's the four heroes who drive things onward. When their lives are in danger, you'll care about whether or not they survive, and if they do die, you'll almost certainly mourn their absence. At the touch of a button you'll be able to listen to what they're thinking - a neat touch that further helps to make the cast feel like solid, organic creations. This ability can also be a massive help in the situations where you need to act fast. There actually aren't that many puzzles in the game, but several of the stickier situations are pretty terrifying when they crop up - and under these circumstances it's great to be able to get a clue from the hero's mind. On a similar note, there are several moments where the game will present you with a genuinely tough choice as to how to proceed, and here again you can listen in to get a handle on the character's response to a situation.

Ultimately, however, the choice is yours - and you'll have to live with the consequences of your actions, even if your characters might not. As I say, it took me roughly 10 hours to finish Heavy Rain, and after I was done I went back to tinker with some of the choices I'd made along the way. Strangely, my prior fears about the game being strictly controlled were both confirmed and assuaged by the final product. The path you take through the story is relatively linear, and some of the seemingly-important choices you make actually have very little bearing on the overall flow of the plot; on the other hand, the game is very clever in the way it folds the important points of difference - and indeed the missing presence of dead characters - back into the overall thread. I've seen five different endings so far, and while they all have certain common elements, I was very pleased by the variation in the conclusions I saw. More impressively, each of the endings seems to work well on its own terms: there are "good" and "bad" endings, to an extent, but the bad ones seem just as valid as the ones which reach a more positive end (I'll stop here now, as I feel like I'm verging on spoiler territory).

A slightly more concerning discovery, and one that's only really apparent on the second playthrough, is that often the player's input is fairly insignificant in terms of the overall way a scene plays out. You can screw things up, but a lot of the time you have to try quite hard to do so, and at times the game gives the impression that you might be in danger when it's actually impossible to fail. In short, the game uses a "rubber band" structure rather than a true branching plotline, and at time the bands are far tighter than how they might appear. Still, this is only really evident when you're coldly testing the mechanics of the game - and doing this feels a bit like pulling the wings off a butterfly.

You can't even go to the shops in this game without something nutso-barmy happening...

As surprised as I am to say it, there's actually quite a bit of replay value in Heavy Rain, but my advice would be to leave the game a while after you complete it for the first time. Go look at the concept art, watch the little making-of videos, and play something else for a week or two before you come back. If you do this, it'll feel that much better on the second playthrough - but be aware that it will never be as exciting as the first time you venture into the great unknown. Beyond this, and the occasional slip in the otherwise superlative animation standards, there's only one criticism I can see people levelling at the game: it's very, very different to anything that's come before. If you're a twitch gamer, the kind of person who values the likes of Bayonetta above all else, you may struggle to get to grips with Heavy Rain. There's not a lot of gameplay in the traditional sense. The scenes which focus more heavily on detective work - largely those featuring Norman Jayden - suggest that the game could have been a lot closer to traditional point-and-click adventures, but that's not the path that Quantic Dream took. Make no mistake, this is an incredible game - but if you're a hardcore traditionalist who's sceptical of anything that doesn't demand oodles of player skill, it's unlikely you'll be falling in love here.

But for the rest of you, for those of you who can open your minds to the possibility of something genuinely new, this is mana from heaven. Heavy Rain is one of the most exciting things to happen to video games for a long, long time. It's not a threat to the old way of doing things, but it does hint at the possiblity of a whole new genre. It occupies a middle ground somewhere between gaming and cinema, and to be quite frank, there's nothing else like it anywhere. If you do plump for giving a pop, I can guarantee that you'll be discussing it - and all the great moments that I've resisted telling you about - for months to come. And if you want a true indicator of the PS3's abilities, and of the true potential of what video games can do, I can think of no better candidate.