Far Cry 3's campaign begins with a quote from Lewis Carrol's Alice In Wonderland bleeding onto the screen, dark blobs morphing into letters like ink spots forming a Rorschach on a handkerchief. As a curtain raiser to the story the subtext here is effective, if hardly subtle: this way madness lies.

But the reason behind this lunacy, and you'll excuse me here for dipping into German philosophers, is summed up perfectly by Nietzsche. "Whoever fights monsters should see to it that in the process he does not become a monster. And when you look into the abyss, the abyss also looks into you."

In Far Cry 3 you fight the monstrous, lost and unhinged inhabitants of a tropical island, and Nietzsche's famous quote applies as much to the mental state of the game's protagonist as it does to every FPS fan's attraction to a form of entertainment in which producing a mountainous pile of corpses is essential to engagement, just as long as it doesn't get in the way of anyone enjoying themselves.

Expressed this way, the player's attraction to Far Cry 3 - or any other shooter for that matter - seems a little sociopathic, and it's to Ubisoft's credit that it explores this appeal without becoming pious or heavy-handed. Far Cry 3 simply tosses the player some guns, sets them loose in an open-world environment and allows them to get on with the business of killing things. Yet during all this free-form chaos the plot tightens on both protagonist and player like a noose.

In a way, it's a trap. Far Cry 3 isn't too different from a tonne of other video games where players are faced with repetitive kill-or-be-killed hurdles to progression, but it does more to chip away at the polite pact that exists between gamers and violent games than any other title released since Rockstar's snuff-film horror show Manhunt. The fact that it even manages to do this while remaining fun throughout is something of a massive coup for the genre.

The player's gateway into all of this is a clean-cut American tourist named Jason Brody, who we see in an opening montage having a wonderful time with his friends and family members before the hiss of his captor reveals the full horror of his predicament. Jason and his mates are in the clutches of a band of pirates who are led by one Vaas Montenegro, a leering psychopath, who plans to ransom them off for a big payday.

I'm not going deep into spoiler territory to reveal that Jason escapes from Vaas and his gang and takes to the island jungle for refuge, but the less players know about the details of the plot going into Far Cry 3 the better. Suffice to say that Jason (and by extension, the player) quickly finds his daily activities changing from a desperate fight for survival into an organised counter-strike against Vaas and the other forces ranged against him.

By employing the well-worn structure of open-world games, Jason turns to the island's downtrodden inhabitants for help. This is a game about a giant map, one where war resources masquerade as mini-quests and activities. There are radar towers players can climb in mini-platform games to fill in the map and unlock weapons from local arms dealers. There are enemy bases ripe for attack, obtaining dole out fast-travel stations and bulletin board challenges in the process. Between gunshots local flora and fauna can be gathered, animal pelts crafted into holsters and bandoliers, and plants brewed into narcotic cocktails that supply Jason with abilities such as repelling wildlife, sprinting faster and holding his breath underwater for longer. And, if you want to let off some steam, there are motorised time trials or wave-based survival challenges to open up Jason's skill trees.

The skill trees are divided along three categories and are represented in the game as tattoos that appear on Jason's left forearm. Every time the player fills up their XP bar through the usual means (killing, exploring, scrounging, crafting and collecting) they're given a point to assign to any number of skills such as aerial melee kills, less weapon kickback, faster movement and bigger loot collection. So the more the player engages with their environment the more Jason begins to resemble a walking slaughterhouse.

Once again, this is hardly groundbreaking stuff mechanically speaking, but it dovetails terrifically with the game's narrative. The closest bedfellow the game has in terms of its story is Yager's homage to Heart Of Darkness, Spec Ops: The Line. But whereas 2K's excursion to Dubai presented violence as a soul-destroying activity, Far Cry 3 opines that it's a necessary tool for survival in the harshest of environments.

As the game progresses, Jason starts to relish in his status as the ascendant alpha male, but he also becomes more and more unhinged. His seemingly natural aptitude for death dealing garners him respect, fear and even sexual interest from a couple of the island's inhabitants, but his mental state starts to veer into borderline hysteria - helped in no small part by the large number of natural intoxicants he partakes in. The developers are careful not to condone his behaviour, but they don't condemn it either. Instead, Ubisoft presents him as a product of his environment and leaves it up to the player to decide what they think of him.

Looming large over the proceedings is Vaas Montenegro, arguably the best villain to emerge in the gaming medium in recent memory. With his unblinking, serpent-like eyes and silken, reedy voice, Vaas comes on like the illegitimate offspring of Iago and Charles Taylor. Flamboyant, intelligent and completely insane, Montenegro is as brutal as he is unpredictable. This is a bloke who allows a captive to flee for sport while screaming threats after them in one moment and casually shoots a helpless victim in the face in another. He's the perfect foil for Jason, and by extension the player, acting simultaneously as their nemesis and their increasingly disturbing reflection.

This is a game where its component mechanics are functional and entertaining, but all serve as a chorus to accompany the melody of the game's massive, engaging world, characters and context. With such a strong single-player mode in place, then, it almost feels like nitpicking to highlight the aspects that hold Far Cry 3 back. But there are some stealth missions in the story mode where being spotted is an automatic fail - and this feels both annoying and archaic, and while minor annoyances in the grand scheme of things are certainly wholly aggravating at the time. Driving can also be a bit fiddly.

Then, of course, there must be multiplayer. It almost feels like chore to talk about Far Cry 3's online modes, although they're competent enough. In co-op players take on the role of one of four ne'er-do-wells and fight their way through a plot that's engaging if hardly memorable. This is a mode best tackled with friends as the developers don't penalise too hard those players who act selfishly - in fact, to a degree, competition is encouraged. Sure, there are in-mission objectives where teamwork is required, but this isn't in the league of say, Left 4 Dead, where a desperate struggle for survival creates a sense of camaraderie between strangers. Still, the customisable load-outs and ability to buff comrades on the fly keep things interesting.

The adversarial multiplayer also has a couple of nice ideas. Firestorm is decent deviation from the usual TDM and Dominations match types; in it players have to set the starting point of the opposite team on fire. They then have to fight for control of a communications link they can use to dump gasoline on the opposing team, which, if they lose, will call in a plane that douses their enemies' zone with water and the mode resets. Players can also buff teammates in online fragfests using a Battle Cry, which can provide speed-boosts, health augments or increased accuracy (read: reduced kickback) on their weapons. So the online modes are decent enough, but it's also doubtful that they'll rob the Halo and CoD lobbies of any significant numbers.

Far Cry 3 shines in its campaign, which is more layered and compelling than any game proffering a power trip through escapist ultraviolence has any right to be. You could dismiss it all as offensive macho garbage, sure, but you could also read it as a unblinking look at the primal appeal of becoming capable at dishing out violence and how the confidence this confers can both attract and repel others. It's the sort of impact that could only be made by a video game, as in this medium neither responsibility for one's actions nor risk to one's well-being are realistic concerns. It's like disconnecting one's mind from reality; nothing is real, everything is permitted and madness is the ultimate get-out-of-jail-free card.

Version Tested: Xbox 360

This review is based on spending 17 hours in the campaign (14 with a review debug build and 3 with a retail copy) and 4 hours in the multiplayer. The debug build was played over two days at a review event in London hosted by Ubisoft.