BioShock

Special mention must go to the design of the Splicers. Alive, they terrify with lunging movements and screeching, barely comprehensible rants. On one occasion, what appear to be husband-and-wife Splicers can be heard screaming domestic abuse at each other, before turning their attention to murdering you once you intrude.

But only on viewing a pummeled corpse do you truly appreciate the violation of humanity they represent. Still dressed in period clothes, yet hideously disfigured, their collapse into genetic oblivion retains a painful human element - some even wear masks to hide their shame from the world. The breathtaking artistry ensures players register a profound sense of sadness at the folly of over-reaching human endeavour.

And such images say more than pages of dialogue. Levine doesn't really do cutscenes, because he doesn't have to. There are other ways to tell a story.

"It's great to be able to tell the core theme of the game just by looking at it," he explains. "You don't need to hear a word; you just look at it and go, 'I get a little bit of what's going on here just by looking at it'."

Equally, rather than subjecting the player to a boring monologue, the pivotal relationship between the Big Daddies and Little Sisters - genetically engineered protectors and collectors of Adam - is captured majestically in a brilliant scene in a theatre.

You watch from a safe distance, as the childish L'il Sis' skips nonchalantly towards a corpse as her Daddy paces menacingly behind. How exactly does she extract the Adam anyway? Ah, by using a giant syringe and then gulping down the contents as if it were a yard of ale on a stag weekend.

A Splicer, craving the Adam, suddenly races in to attack the Little Sister, at which point the monstrous, hulking Daddy shudders into life and savages the Splicer to death. Even though the scene is obviously scripted to a degree, by 'happening' upon it and sneaking around for a vantage point, the illusion is brilliantly maintained.

The Big Daddy/Little Sister relationship, and how you deal with it, is the game's nexus. Little Sisters are your source of Adam, which you'll need to develop your special abilities. And to get at that you have to get to them, by getting past them. One of the game's central themes is thus communicated .

The story is moved on in other ways, notably through personal audio files and logs you'll find. Finding some of these become mini-missions in themselves, containing information essential to progress. The rest are strewn throughout Rapture awaiting your attention. It's up to you whether you want to go that deep, but Levine claims they provide a "novelistic level of detail" if you want it.

It might not be a particularly realistic way of telling the story of Rapture, but it should mean that the storyline is never over-bearing in a 20-minute Final Fantasy cutscene way, which many gamers will appreciate.

Choice is all. Re-emphasised by your first proper encounter with a Big Daddy late in the stage. You can stay and fight, using every trick and tactic at your disposal to wipe out the brute to get to the Adam. Or you can just run away like a coward, but forfeiting the potential upgrade to your abilities.

The game's not entirely free-form, of course, and dynamic goals will be set as you complete various tasks. To help you navigate, a compass point will lead the way to key areas. And maps and messages are all stored via a menu system for you to check up on at any time.

In terms of impact and atmosphere, our initial experience with Bioshock thrills and captivates in this taster of Rapture's hidden depths. Other areas you'll visit, revealed but inaccessible on a menu, include Arcadia, Hephaestus, Point Prometheus, Neptune's Bounty, Fort Frolic and Apollo Square.

There are a few hangovers from old-style game design. Explore and find heat Plasmid to melt ice and progress; find telekinesis to move object and progress, and so on, which jar slightly with the otherwise impeccable structuring. Limited ammo and the need to improvise also requires a lot of weapon and action swapping on the fly which can prove a little clumsy and consuming at first, though hopefully familiarity and practice will cure this issue. And when using the wrench to tackle a horde of Splicers, resorting to wild, aimless flailing is not uncommon as you struggle to get a hold of the situation.

But these are minor niggles far outweighed by our thirst for further exploration of Rapture's astonishing, unique innards, and the dizzying scope and potential of the main action, only hinted at in the early stages as players are eased in.

At the section's climax, we meet Tenenbaum and a Big Daddy-less Sister is at last offered to you for Adam-grabbing immolation.

So here we are again. Rescue or harvest? Harvest or rescue? Tenenbaum, whose unchecked ambition, after all, caused this whole sorry mess, is begging you to spare her. Atlas, however, observes that these genetically modified freaks have already been stripped of their humanity; and you need the Adam to survive.

The game then spells it out to us. If we harvest, we get maximum Adam, but she dies. If we rescue, we get substantially less Adam but, Tenenbaum desperately appeals to our conscience, it will be worth our while. Our call.

We grab the girl and draw her right up to us. She's screaming, fear etched into her face, hopelessly, pathetically writhing and trying to push us away. "No! No! NOOO!" She still seems pretty human to us...

Sod it. "Harvest".

The hysterical child moves briefly out of view, there's a skin-crawlingly grotesque sound effect and... Well, you'll want to see this for yourselves.

"How could you do this to a child?!"