You hear it in many movie trailers: “Imagine a world…”

Building those worlds poses a weighty challenge to authors of any fiction. In video games, where works with no basis in reality are the norm, the challenge grows in difficulty. Not only should a video game world stand alone in its mythic scale, it should motivate the player to explore it exhaustively.

“Bioshock” accomplishes both these goals with awesome success. Its dazzling but desolate underwater city of Rapture marries America's art deco aesthetic of the 1930s with the carnage and devastation of “Resident Evil 2's” Raccoon City. Blood splatters translucent glass brick walls, neon marquees cast harsh shadows against dark lobbies and elegant ceiling fixtures loom menacingly in superb graphic splendor. This environment of exquisite horror delights your eyes when you're not in danger.

New to the PlayStation 3, this first-person shooter from 2K Games situates players as a mysterious protagonist named Jack. After his airplane crashes in the middle of the Atlantic Ocean, Jack escapes the wreckage and swims to a nearby lighthouse and descends into Rapture via an elevator. An Irish guide named Atlas makes contact with Jack via radio and briefly acquaints him with the maritime metropolis he unwittingly found.

The only surviving denizens of Rapture are Splicers, deranged humans who greet Jack with hostility. Their genes have been rewritten many times over by Plasmids, superhuman upgrades that can halt male baldness or even empower someone with telekinesis. To survive the Splicer hordes, Jack must not only wield the traditional range of FPS weapons - pistol, shotgun, grenade launcher - but power-up with Plasmids as well. Obtaining those means overcoming the other major nemesis of “Bioshock”: Big Daddys. These diving suit-clad behemoths with drillbit hands and punishing rivet guns protect Rapture's “Little Sisters,” outwardly sweet young girls who carry ADAM, the cellular material that permits Plasmid use.

Though “Bioshock” front-loads its more savory story elements, the game paces its exposition well enough to let the player absorb every nuance of the new world of Rapture. An abundance of audio diaries slowly peels back the layers of story surrounding Rapture's establishment, the Ayn Rand-inspired ethos of Rapture's founder, Andrew Ryan, and the chain of events that wrought the city's decay. Minimally over-the-top voice actors perform the brief monologues, which players can hear without interrupting the game.

Before you can ponder Ryan's aphorisms in great depth, Rapture's citizenry attacks. Splicers can be blown away like the foes of any other shooters, but Rapture gives players several fun avenues for inventive offense involving Plasmids. Jack can incinerate Splicers standing in oil slicks, electrocute foes knee-deep in water and swarm them with hornets. Enemy weaknesses are revealed through a clever photograph system that rewards snap-happy players with damage bonuses against foes Jack frequently captures on film.

Gun turrets and cameras that would damage Jack can be hacked to instead target enemies. In the enjoyable hacking minigame, you must rearrange pieces of pipe on a grid to create a connection from one point to another. If the fluid flowing from the first point is halted, the device will short circuit and harm Jack. Vending machines, safes and other mechanized stations can also be hacked to line Jack's pockets with helpful items.

Stratagems like Plasmids and turrets are especially handy against Big Daddys, who eschew the patterned offense of mini-bosses in other shooters and simply bull-rush unprepared players into oblivion. The select other bosses in “Bioshock” are also best battled with pure attrition in the form of potent artillery and Plasmids. The absence of finesse in the game's combat proves a thoughtful counterpoint to Rapture's aesthetic - and to other shooters, which often abide by the same formula of tiered, larger-than-life foes all susceptible to the same firepower.

Though every square inch of Rapture's sinewy layout is dotted with the detail you would expect from a fully inhabited city, there are a few faults in the game's level design. Players will find themselves backtracking over some areas and going out of their way to explore superfluous ones. Those latter portions of Rapture lend the impression of ideas 2K liked too much to cut, and this approach to “Bioshock's” design also explains its slightly drawn-out length.

The game's other persistent problem is its save system. Should Jack die, he is restored at checkpoints called Vitachambers with half as much health and the same supply of weapons and other inventory. But enemies retain as little life as Jack left them before he perished, so players can kill them through sheer perseverance. Even the imperative to survive from one checkpoint to the next is displaced by the ability to save progress to the hard drive at any point in the game.

It's nonetheless hard to harp on “Bioshock's” imperfections in light of its myriad accomplishments. The game offers players a compelling thematic take on the one province of games that distinguishes them as a medium: choice. Players first face a simple moral dilemma. You can decide whether to harvest the Little Sisters - swiping all their ADAM but killing them in the process - or save them by purging the young girls of less ADAM but letting them live.

When Jack's real origins are revealed midway through “Bioshock,” players will confront larger questions concerning the choices they make in Rapture. But choosing to play the game and visit this stunning city should be a less difficult decision.

David Wilcox

253-5311 ext. 245