For the player, it is mostly about discovery--a slow, dawning discovery that is constantly being informed. For this reason, it is difficult to discuss what makes BioShock compelling without referring to specific environmental and narrative elements in the game, but I will attempt to avoid particularly crucial spoilers without warning.

BioShock's introductory cinematic, already in a first person perspective, notes that the game is set in the mid-Atlantic in 1960. It opens in a commercial aircraft just moments before the plane hits heavy turbulence and plunges out of the sky and into the ocean. The player is given control at that point and, after swimming to a nearby lighthouse, watches the ruined plane sink down below the ocean's surface.

"Who knows? Maybe we'll see that plane again," mentioned Irrational Games creative director Ken Levine, who introduced the game before setting the crowd of assembled journalists loose to play through the game's first few hours.

In the lighthouse, ornately adorned with iconic art deco embellishments, paintings, and classical sculpture, the player goes the only way available--down--to find a single, curiously inviting bathysphere. Upon entering, the bathysphere descends out of the lighthouse and along its preset course through the water, giving players their first glimpse of Rapture, the failed utopia that is at the center of BioShock. While on the ride, players will pass by sea life and grand underground skyscraper-like towers. Levine noticed that every structure seen during the bathysphere ride will be visited by the player over the course of the game. The effect is somewhere between Half-Life's unforgettable tram ride, offering just suggestions of the non-stop action to come, and Myst's pristine but deserted, realistic but surreal visual style.

"This game is all about idealists, about ideas going too far," Levine mentioned to me during a conversation after the play session. "The whole game is about that."

The bathysphere docks and the player is given the first glimpse of the world inside Rapture, and it is a startling change from the gleaming utopia seen just moments earlier. From behind the device's glass barrier, a man is brutally killed by some kind of mutant with scythes for hands. The bathysphere's door opens, and the Objectivist parallels are driven home when a new faceless voice is introduced, that of the guide character Atlas.

Atlas is of course the Titan from Greek myth tasked with endlessly supporting the celestial sphere on his back. In Rand's novel, one of the protagonists suggests that Atlas shrug--that is, throw off the weight of the world. The implication is that the world's intellectual and industrial giants should not be constrained out of false duty to humanity, the same implications made by Andrew Ryan as the catalyst for the creation of Rapture. The world of Rapture is plastered with reminders of its ideals; as one slogan reminds us, "The Great Will Not Be Constrained By the Small." Atlas is set up as a foil to Ryan, an opposing disembodied voice. Throughout the game, Ryan espouses his ideals, and Atlas condemns them.

Atlas promises to help guide you to safety if you will help him find his family. At this point the game proper begins. The interior of Rapture is desolate, decayed, destroyed. Water seeps in through cracks and seams, objects are broken and scattered, posters are faded and torn, and frustrated graffiti adorns the walls. "Ryan doesn't own us," proclaims one message. "Let it end, let us ascend," pleads another. Most striking--and suggestive--is the spray-painted assertion, "Atlas was right."

You soon find a wrench, which comes in handy when attacked by another of the crazed killers seen earlier. Combat in BioShock is stark and brutal. Enemy encounters are frequent, but by no means constant, which makes moments of silence in the dim, quietly chaotic world all the more nerve-wracking. Killing the enemy with the wrench is a visceral experience. Blood ejects from his head in viscous Gears of War-like globs, and the sound design is sickly convincing.

Continue reading for details on BioShock's player modifications, Big Daddies and Little Sisters, and combat nonlinearity.

The bizarre pairs of Big Daddies and Little Sisters are a crucial part of BioShock. Little Sisters--ostensibly young, vacant-eyed girls--are the only individuals capable of obtaining Adam, essentially the currency of Rapture used to purchase the upgrades that become instrumental to gameplay. Big Daddies--massive, iron-clad, drill-armed hulks--are the Little Sisters' protectors, and will go to any lengths to ensure no harm comes to their petite charges. Trailers and promotional materials for the games have painted, as the characters' names suggest, a bizarre form of a father-daughter relationship in the pairings.

The story behind the Little Sisters is sure to be a major plot point in BioShock, and the player's choices surrounding them will have direct gameplay implications. At numerous points throughout the game, you find yourself in a position to either let a Little Sister go free or to harvest and acquire her Adam--which you must kill her to do. During the first instance of this frustrating moral choice, you are being pelted with arguments from two opposing sides about the nature of the Little Sisters and the importance of your decision--one character paints the Little Sisters as aberrations, one calls for compassion. Of course, the idea of getting more Adam with which to enhance your character is a tempting proposition, but Levine promised that there are other, longer-term rewards for setting the girls free. During my play session, I found myself wrestling with the choice for what must have been several minutes.

I asked how much range there is to BioShock's gameplay experience, given the two approaches. "It's very different," he said. "The reward system is very different between harvesting and saving. It implies a different route, and there are different gameplay things but also different story elements." He declined to elaborate further, understandably wanting to keep as much as possible about the progression of the game under wraps.

Of course, to be in a position to decide the fate of a Little Sister in the first place will require going through a Big Daddy. BioShock generally aims to allow the player a measure of choice in combat tactics--the powers offer different ways to customize one's character, and the weapons each feature three different types of modifications as well as three different types of ammunition each. A pistol might be modified to hold more ammo or fire more powerful slugs, while a grenade launcher might be modified to direct its grenades' blast away from the player in order to avoid self-harm. That said, most enemies can still frequently be taken head-on if the player so desires, in the style of most first person shooters.

Not so with the Big Daddies. Big Daddies are monstrously tough and incredibly powerful, and require some level of foresight to battle effectively. There was one Big Daddy combat encounter in the hands-on demo, but we were also shown a few different approaches to the same encounter, as played by an Irrational team member named Dean. In one instance, Dean ran into a room with Big Daddies and other assorted enemies. He used the Rage power on the Big Daddy, causing the big guy to go berserk and start attacking the other enemies. This gave Dean a chance to take some well-aimed crossbow shots. Of course, once the Rage wore off, the Big Daddy was rather peeved, but Dean had also set up a perimeter of trip mines around the Big Daddy, which proved to be the foe's undoing. In another instance, Dean used the game's hacking ability (represented by a brief, enjoyable pipe-constructing mini-game) to convert some enemy turrets to do his will. He then used his Incinerate ability to light numerous enemies on fire; when they ran into a pool of water in panic, he zapped the water with lightning, fatally electrocuting all of them.

Continue reading for thoughts on BioShock's atmosphere and storytelling techniques.

There seems to have been a particular moment when things went wrong, but it was no single factor that did it. Rapture's fall was a physical breach, a scientific disaster, a psychological breakdown, a moral decline--overambition to the highest degree. I will decline from elaborating on the content of specific points, but suffice it to say there are many avenues by which to discover just what happened.

Transmissions from Ryan increasingly demonstrate the society's immense hubris. Scattered audio logs from cirizens of Rapture tell the stories of individuals before and during the decline--in these tales are nestled nuggets that refer to greater events or suggest a more overarching social dysfunction. Different types of advertising reveal how inhabitants spent their money--and, therefore, what they strove to acquire and what their desires had become. Lingering Rapture residents clinging onto their last scraps of sanity provide a distorted but illuminating link to life prior to the end, while photographs depict crystallized images of the Rapture of ideals. Even the graffiti scrawled on the walls contributes to the richness of the world. It would be nearly overwhelming were it not so endlessly engrossing.

(Skip this paragraph to avoid potential spoilers.) In a early moment of invigoratingly mounting horror, you come across the offices of a plastic surgeon who, after perfecting the art of gracing faces with traditional beauty, still finds himself driven to further his craft. Slowly, and piece by piece, you begin to realize that, like abstract artists before him, the doctor eventually abandoned notions of traditional beauty and set out to realize his vision in less predictable ways. Picasso-inspired target images and diagrams reveal the artistic approach the doctor took with the faces of his trusting patients. "We said, 'Wait a minute, what about this plastic surgeon who's an idealist about beauty? How would that go wrong?'" recalled Levine when I brought up the sequence. "I started writing all these ideas that came out of that, then some other guys said they were going to build these little Steinman shrines throughout the level, giving more hints to his character."

I asked Levine to elaborate on his attitude towards narrative and game design. "If you've got to just tell the player, then it's wrong," he said regarding exposition. "The whole city is a visual metaphor--this city that looks like their ideals. All the water pouring into it is basically what happened to their ideals. It's all visual metaphor. We call it mise en scene, you know, because we're pretentious fucks, with these little visual moments we build where you can look at it and say, 'Oh my God, I know what happened here,' rather than reading some extensive thing. It's a storytelling technique."

(I guardedly admitted that I had used the term mise en scene myself in a recent conversation about Valve's Half-Life series. "Ah, so you're a pretentious fuck too!" laughed Levine.)

If there is anything that might be worrying about BioShock, it is simply that the amount of gameplay, atmosphere, and sheer information contained in the first few hours is so densely packed that it is difficult to imagine how a team could reasonably create a game that carries on at that pace through the entire campaign. If it does, however, I have no doubt that Levine and his crew at Irrational Games will have managed to create something that will prove to be among the more complex, weighty, visceral, and atmospheric games in recent memory.

Irrational Games' BioShock is set to be released in North America on August 21 for PC and Xbox 360. The game will follow in Europe on August 24.