Look at a map of North America and you're staring into the last four hundred years of the country's history, the layout of the states revealing hints of a westward expansion that was first fiddly and hard-won, then swift and careless. On the eastern side of the continent, the shapes are strange and irregular, each kink in a border as likely to be the result of a land dispute as it is a river or mountain range that had to be worked around. Look west, however, and someone's ditched the niceties and broken out a ruler, carving the territory up in straight lines as much as possible, dividing the wilderness sight-unseen. As time passed, this unexplored chessboard of empty deserts and dusty canyons became home to a hesitant scattering of frontier-posts and shantytowns, populated by hopeless cases and gun-toting weirdoes. The lost and damned, in other words: a promising landscape for videogames, and a perfect setting for one developer in particular.

And yet there are surprisingly few good games about the Old West. Certainly, the 8-bit anticlassic Custer's Revenge got things off to a shaky start, but to this date, the decent titles - the phenomenal Stranger's Wrath, and the largely serviceable Gun, for example - can be counted on the fingers of one hand, even if you happen to have lost a few digits whittlin'. Red Dead Revolver, Rockstar's first foray into the genre, was competent and occasionally brilliant, but, picked up half-completed from Capcom, it was something of a development mongrel. With the sequel, however, the House of Liberty has a chance to build the title from scratch, and hopefully, in the process, provide a cowboy game that captures the atmosphere you want when you head out west - the tension, the shootouts, and the brooding, dusty menace - in a way that so far, bizarrely, only Oddworld has been truly able to do.

If Revolver was a Spaghetti Western, Redemption is a grim-faced Butch Cassidy, moving the clock forward to the turn of the 20th Century, and exploring the nasty derailing that ensued when the frontier culture collided head-on with the modern world. It's a tantalising agenda, and one that colours every aspect of the game, as protagonist John Marston, once a bandit, now trying to get by as an honest man, finds himself roped into helping the Bureau, the government agency created to tame the west, when they give him what Rockstar's coyly referring to as a "terrifying ultimatum".

Hopefully, that ultimatum's a little more involving than, "Either the beard goes or I do." But, however the mystery eventually unfolds, Rockstar's already created another of its signature leads: a brutal victim, trapped between their own wishes and the plans of others, or, if you prefer, caught within the promise of the sandbox environment, and the quiet tyranny of the missions layered on top.

Rockstar's playing the Western genre straight, then, and building on it much the way you'd expect it to, with the open range transformed into an open world split across three massive areas, divided into Frontiers, Plains, and Mexico. The result is a plot of land which, taken as a whole, is significantly bigger than GTAIV's Liberty City. But while the developer is keen to underline the size of Redemption's stomping grounds, it's the wildness of it that is initially most startling, and the first indication comes with the lead character. Marston, all gun-belts, Stetson, and itchy trigger fingers, is a peculiarly haunted presence, his eyes darting back and forth whenever idling, as if he's nervous and perhaps slightly paranoid about the space into which he's been dumped.

And, flung into the game for a quick developer playthough, he has every reason to be. Frontier is a vast expanse of dunes and bluffs, golden mountains rising on the horizon, and tumbleweeds rolling through the foreground. With a huge draw-distance and a creepy soundtrack in place, there's a palpable sense of isolation, but Redemption's world is far from empty, the wilderness between towns alive with creeping wildlife (for the first time in an open-world title, Rockstar's pouring critters into the sandbox, with an elaborate ecology that fights and feeds all by itself) and packed full of entirely unpredictable encounters with the locals.

You can choose to ignore most of the distractions the game flings at you as you trot through the desert, but they still offer glimpses of a stark and ungovernable environment, as the next rise reveals a rotting corpse tangled in amongst the scrub, or a strange plume on the horizon, which may emanate from drunken good ol' boys gathered round a campfire, or the dust flung up by a group of desperadoes dragging a local farmer behind them. Frontier doesn't just seem dangerous, then - it feels promisingly unhinged.

Transport around such a huge space is as volatile as the rest of the wildlife. Powered by Euphoria's real-time animation system, which allows for an unending parade of saggy, staggering deaths, each horse Marston finds, whether he steals it from a town or tames it from the wild, has a different set of traits, ranging from speed and toughness, to general orneriness, all of which reveal themselves in wilful handling. His rides are easily spooked, too, with snakes, gunshots, and even reckless over-spurring causing them to throw him if he doesn't treat them right, suggesting horse management may add a fascinating wildcard to many of the game's missions.

With the wilderness drawn with such surprising force, it's harder to gauge what kind of order Rockstar is seeking to impose on such a convincingly lawless world, and while the three brief missions we're shown focus heavily on combat, they reveal little in the way of story or overall structure. The first, a tense hostage exchange in an sun-bleached ghost town - this being Rockstar, it's a trap, of course - throws Marston straight into the middle of a dusty shootout, with a nice range of cover options (players can hide behind rocks, fences, and even horse carcases if they're really desperate), and a handful of Dead-Eye special moves for when the odds stack up. The first of these is a standard slow-mo, while the second allows Marston to line up as many shots as possible on multiple enemies before unleashing them all in a single deadly volley, adding a deft tactical dynamic to the 360-degree staging.

Two subsequent missions give a taste of other, equally traditional scenarios, the first riding shotgun on a fleeing stagecoach, the second on horseback, protecting a battered steam train from bandits. The stagecoach offering has a pleasant hint of shooting gallery to it, with blindfire to exploit and a range of guns at Marston's disposal, from the thuggish close-up blast of a sawn-off, to a carbine useful for picking people off in the distance. Meanwhile, shooting desperadoes looks just as satisfying on horseback, which turns out to be a lot more interesting than blasting away at someone out of the window of a Blista Compact. Marston's both more manoeuvrable and more vulnerable than Liberty City's motorists, a few well-placed volleys taking his nag's legs out from under him and dumping him into the sand, on foot and at a significant disadvantage.

An ambush and two escort runs, then, but while the missions we're shown may be fairly conservative, there's an undeniable freshness in the old west details, leading to a slight thrill every time you select not just a rifle, but a Winchester from the weapon menu, shoot a man's hat off during a chase, or stumble across robbers with bandanas covering the bottom half of their faces.

Due to the general scarcity of decent Western titles, and the developer's own skill at mimicry, Rockstar's latest is shaping up to be that rare game in which it's still exciting to see your favourite genre clichés enacted as much as undermined. And while we've only been given a quick glance at a gigantic title, it's more than enough to remind fans of Revolver what a perfect match Rockstar's found in the Wild West. With a setting that offers a handy means of exploring the company's fascination with brutal morality, while simultaneously providing a neat framework of cinematic references to hang the whole thing on, Red Dead Redemption sees Rockstar shooting from the hip - and, so far, it's hitting most of its targets.