After thousands of giant, plague spreading rats appear overnight in Dunwall’s sewers it’s something of an understatement to say that the city has a vermin problem. So it is that corpses are soon piled high on the streets, the remaining populace lives under martial law and even the city’s politicians are in turmoil – following the assassination of the Empress.

Dark times call for a hero, and so step up one Corvo Attano, former bodyguard to the fallen Empress who has sworn to avenge her and rescue her daughter, who was kidnapped during the assault on her mother. First however, he’ll have to find a way off death row, having not only been witness to the murder of his charge – by killers adept in the ways of black magic no less – but framed for her death too.

Choice is everything in Dishonored, and your first decision starts here. Do you run your sword through each of your jailers’ hearts, as you systematically seek vengeance against every person who wronged you, no matter how tenuous the link? Or do you knock them out instead, so allowing them to return to their families upon coming around?

If you do elect for the bloodier path then expect the city’s shadows to grow ever inkier, its rat population thicker, and its plague more deadly as darkness begets darkness; just one of the ways in which Dishonored subtly feeds back to you to as it tracks how you fare within the confines of Dunwall.

Once clear of prison and out blazing a trail of justice against those in the higher echelons of society you’re told were behind the attack such options in your approach only increase. Indeed, upon meeting the mysterious ‘Outsider’, you even come into possession of the same dark arts that saw the Empress’ assassins dissipate into the ether after they’d completed their grisly task.

So it is that upon buying powers (with runes collected throughout the city) you’re able to instantly transport, or ‘Blink’, from point to point within your line of sight; conjure devouring rat swarms; throw enemies back with blasts of wind; or possess rats, fish and eventually humans, as you look to infiltrate the hideouts of your targets with as little (or as much) fuss as you feel is appropriate.

Your weapon choices will expand too, giving you access to pistols, sleeping darts, mines, grenades and more. Weapons can even be combined with objects in your vicinity so that grenades can be lobbed onto tanks of whale oil (which power the city) to create huge explosions, or rats attached to mines to creating scuttling bombs.

Of course such choice would be for nought if the game’s setting, the smarts of the city’s guard and the imagination of both missions and narrative was not up to scratch. Happily I’m able to report that Dishonored has no such problems, as everything from its distinctive visual style – a beautiful blend of cartoon and realism – to how an isolated guard will run and raise the alarm rather than confront Corvo make for a compelling experience.

Indeed Dishonored joins that rare breed of games – the likes of Deus Ex, System Shock 2, Half-Life 2 and so forth – which show the heights to which games can soar in the right hands. Perhaps by way of example it’s best to describe one of the missions – take the ‘Golden Cat’ mission already detailed on Bethesda’s YouTube channel.

During the mission Corvo must infiltrate the Golden Cat bathhouse which, given the unseemly world of Dunwall’s upper classes, doubles as a brothel. His targets are the Pendleton twins, politically powerful brothers who aided the Empress’ killers and, as you might have seen on YouTube, each can be taken out by either a full-on bloody assault or by stalking them across the bathhouse to where they’re most vulnerable – one of them coming to a very unpleasant end in the bathhouse’s steam room for example.

What you don’t see on YouTube is that there’s a further choice, here Corvo can visit a local gang leader who will spirit away the twins away without Corvo having to bloody his sword at all. All he asks for in return is the code to a local art dealer’s safe, before hinting at where dealer might be found.

Therefore it’s entirely possible for you to complete the mission without once laying eyes on the Pendletons; remarkable and a true commitment by Arkane Studios to make player choice the single most important part of their game. That same freedom applies to every mission meaning that, on the first play-through at least, whole sections of potential gameplay are likely to go unseen by the majority of players.

Dishonored’s scope is hard to judge as it’s theoretically possible to run through the game’s mandatory objectives in say 10 hours or so. But then what would be the point when Arkane have made all of Dunwall’s nooks and crannies cry out for exploration? You might also want to challenge yourself to beat the game without using any powers say, or without killing anybody – all of these objectives and more are attainable with the right amount of dedication.

There are a few issues, most irksome being screen-tearing (this was on PS3) when turning left and right. Teleporting can sometimes annoy with the precision required to ensure you appear at your intended destination too, while juggling all your powers and weapons can be somewhat laborious at times. These slight criticisms do tend to pale into insignificance however when compared to the overall experience that Arkane have created.

Praise must also go out to the visuals and scripting that elevate the game still further. Watching the mechanical ‘tallboys’ dominate the dimly lit streets on their stilt-like legs is mesmeric, discovering clues by eavesdropping upon the well-written conversations of members of the city’s guard is truly brilliant, while the confidence and technique Arkane have displayed in allowing complete freedom to explore the city is nothing less than astounding.

Buy it, revel in exploring Dunwall and, once you’ve got to grips with silently threading your way through sewers and over rooftops, start it from scratch and really play it, for Dishonored is a rare vintage worth savouring.

Format: PS3 (tested), Xbox 360, PC
Price: £34.99-£49.99
Developer: Arkane Studios
Publisher: Bethesda Softworks