Two terrified men dangle in the air. They've been bound, gagged, and left to hang from a metal overpass. On either side of the valley, at a distance, there's a pair of snipers, aiming at the prisoners with their high-calibre rifles.

The hanging man on the right was caught stealing water; the hanging man on the left was ordered to punish the water thief, and responded by executing his family. Now one of the two must die. And you? It's your job to choose who gets the bullet.

It's clear at moments like these that Spec Ops: The Line is aiming for maturity. It's a third-person shooter, and as such it's got all the gung-ho hijinks you'd expect from the genre: Roadie runs into cover, terse firefights, and skull-popping headshots. But when it's not asking you to deal with waves of gun-toting hostiles. The Line has a braver demand to make: it wants you to think.

"A lot of our inspiration comes from Apocalypse Now and Heart of Darkness, in terms of narrative, and also things like Full Metal Jacket and Platoon," says Denby Grace, executive producer at 2K. "You can draw comparisons with what those films did to war movies back in the '70s and '80s. They changed the stories that were telling about war movies. War movies before that were quite simplistic; they were still great - Kelly's Heroes, John Wayne war movies, stuff like that. But what these films did is they started telling personal stories about the soldiers in combat, and about how war can actually afflict someone, change someone, and really fuck with someone."

Apocalypse Now took the core plot from Heart of Darkness, Joseph Conrad's seminal critique of Western colonialism, and re-imagined the whole thing as a nightmare from the Vietnam War. Now Spec Ops transplants the story for a second time, unfolding in the ruins of near-future Dubai. After Roland Emmerich-level sandstorms hit the city, the US military launches an evacuation programme under the leadership of Colonel John Konrad. As the situation worsens Konrad refuses to leave, remaining behind as Dubai disappears in a whirlwind of sand. Several months later a trio of Delta Force ops are sent in to investigate, with the player assuming the role of team leader Martin Walker - voiced by Nolan North.

It's not spoiling much to say that Walker and his men soon find themselves confronted by a lot of angry men with guns. Spec Ops: The Line may be channelling Apocalypse Now, but in immediate terms it feels much closer to David O Russell's Three Kings - a film that successfully blended biting satire with action movie heroics. Yager Development's game has far less emphasis on black comedy, but there's certainly a similar juxtaposition of bombastic gunplay and (comparatively) sober reflection on the traumas of war.

Much of the action follows the yellow brick road of shooter archetypes. There's an on-rails chopper-on-chopper sequence in the game's opening moments, while the ensuing on-foot combat sticks closely to the genre's core staples. Allies are directed via simple, single-button commands. Hostiles are flushed from cover with well-aimed grenades. Gun turrets are flanked, liberated from their operators, and then turned against waves of incoming enemy fodder. But The Line isn't without its own ideas either: the sand-covered terrain allows Yager ample opportunity to pull the rug - and indeed the very ground itself - out from under the player's feet, collapsing the scenery at a moment's notice, or disrupting a shoot-out with theatrical sandstorms. The latter have an almost hallucinatory quality, saturating the screen with a sinister red tint and turning both friend and foe into staggering silhouettes.

And then there are the quieter moments. When it's not busy swamping you with people to shoot, The Line keenly up serves a procession of military barbarism, the products of a Dubai that has sunk into a private hell of its own construction: mass graves, captives tortured with phosphor, and the morbid dilemma presented by two hanging men, a quartet of snipers, and the order to kill - an order that can be disobeyed, but only with dire consequences.

"One of the things we keep getting asked is, 'Is it possible to save everyone?' In this instance, no," explains Grace. "One of the things we like is that the decisions you have to make are either bad, or worse. You're not a superhero, and how this affects you is one of the things we're playing with."

Of course, a decision like this is only hard to make if the player has actively invested in the world you've constructed. 2K and Yager are confident they're filling a niche by creating a shooter that focuses on story, but whether the gaming public agree remains to be seen; these days, Call of Duty's campaign is widely regarded as little more than a value-add. All the same, Spec Ops: The Line has loftier narrative ambitions: on current evidence it'll owe more to Francis Ford Coppola than to Michael Bay, and for that we can all be thankful.