Sometimes, it's the little things that stand out. With Brink, it's the "vip" you hear as bullet fire whizzes by your head; it's the third-person camera perspective the Operative class can view the game in when hacking terminals; it's the Mirror's Edge-style movement, triggered from one, very S.M.A.R.T. button; and it's the cool hoodie you've customised so you look the part when stealthing about. But, as experience has taught us, so many good ideas remain just that, and fail to gel together into a cohesive, fun whole. Will Brink suffer a similar fate?

No, is fast-talking Splash Damage CEO Paul Wedgewood's answer. And to prove it, he plays Brink for half an hour at publisher Bethesda's Gamers Day event in France, showing an assembled throng of journalists that his shooter is not just great in theory, but great in practice.

I'm loath to say that Brink blurs the line between offline and online, because it's been said of the game a million times before, but really it's true. At its core Brink is an evolution of Splash Damage's still popular team-based competitive multiplayer FPS series Enemy Territory; eight versus eight, two rival factions, a near-future urban setting, impressive character customisation, persistent player progression and lots and lots of upgrades. But - and this is the cool part - it's a game that does its very best to fool you into thinking you're playing an entirely different game.

Say, for example, you start a Resistance mission on your lonesome. You'll be playing with seven AI-controlled comrades against eight AI-controlled Security bots. But if you're connected to the internet, those bots can be replaced by real world players who slot seamlessly alongside you, or against you, turning Brink from an offline shooter into an online shooter in the blink of an eye.

That, in of itself, isn't so revolutionary. Brink's genius, however, is in how it dynamically reacts to what players are doing and what class they're playing. Objectives, picked up from captured command posts, update according to the to and fro of the match and the class make-up of the players. Say, for example, you're playing as the Soldier class. The game will offer you objectives of the blowing stuff up variety, usually to be completed using the soldier's heavy explosive charge. But if you're a sneaky Operative, you may be offered a mission to hack a computer terminal. Or, if you're an Engineer, you may be tasked with placing landmines and turrets.

Brink is being built using a version of id Tech 4 modified so players permanently host servers just in case someone drops in to play

Why should I bother to do anything other than shooting people in the face? Good question. Splash Damage openly admits it'll bribe players with experience points to get them to do some of the more team friendly objectives. You'll get loads of XP for healing as the Medic, for example, for capturing command posts and, generally, for doing the kind of stuff that tends not to grab the headlines, but helps inch your team forward towards its ultimate goal.

Paul's shown Brink's good ideas off in previous demonstrations, but it's reassuring to see them come together. And it's even more reassuring to see that in focusing on making those good ideas as good as they can be, Splash Damage hasn't forgotten the bread and butter; Brink's weapons, from pistols and sub machine guns to assault rifles and grenade launchers, look and sound fantastic. Each has a unique impact and feel, and carries real, satisfying weight. Player movement, fuelled by S.M.A.R.T., looks responsive and fluid. For all of Brink's clever line blurring, simply running and gunning and shooting someone in the face looks like it'll be immense fun.

Weapon customisation looks just as deep as character customisation - you can add scopes, silencers, muzzle breaks and more.

But still, Brink's good ideas keep on impressing, punctuating Paul's gameplay demo like little spikes of innovation. Take Brink's arrow, which sits at the top of the HUD and points you towards your objective, for example. It works like most in-game pathfinding guides, but it's dynamic, re-routing players if they try to find alternative routes to an objective. Paul shows it off: as an Operative, he picks the "plant a hack" objective from a command post. The arrow, like a Sat-Nav, encourages him to take a route straight up the main road for a frontal assault on the "warden's office", where the Resistance hope to steal important codes. But Paul decides an alternative route would be better suited to the Operative's stealthy skills. He dives over a fence to his left, and the arrow automatically re-routes, pointing him towards an unmanned back route into the warden's office.

The good ideas keep on coming. Some of the class abilities, unlocked as you progress up the experience ladder, are brilliant. "Sense of Perspective", for example, switches the camera to third person, allowing players to keep an eye out for enemies as they're locked into completing objectives. "Combat Intuition" acts as an early warning system, triggering a yellow bar on the HUD whenever the player is in an enemy's crosshairs. "It doesn't happen fast enough for me to use it like an aim bot," Paul insists, "but it does mean I can usually find cover or concealment or fortification. I have a chance of fighting back."

The floating utopian eco-friendly Ark in which Brink is set is another good idea. Visually, it sits somewhere between Mirror's Edge's pristine blues and whites and the exaggerated proportions of Team Fortress 2. Brink tells the take of a brutal conflict between two bitter enemies, but it's not a gritty game. It's vibrant and colourful, which should help it stand out from the many dour shooters that litter our store shelves. It's packed with detail, and... stuff... the result of level design set free by Brink's S.M.A.R.T. button. "Our level designers love it because they can have tons of debris and detail we couldn't have previously," Paul says with a cheeky laugh.

For the first time, Paul shows off the Security Command Centre, heavily resented by the refugees who live in the Ark's shanty towns and slums. And, for the first time, he shows off the Resistance, a cult-like environmentally friendly counterpoint to the ruthless Security faction. As a member of the Resistance, Paul prepares himself to break into the Command Centre and break out an imprisoned pilot, called Nechayev.

The Resistance psych themselves up for the impending attack in suitably adrenaline-pumping cutscenes - not what you'd normally associate with Splash Damage games. In a later mission, in a district called The Reactor, the Resistance are at it again, talking about how they're going to destroy the Ark's horrible fusion fission reactor or die trying.

Play nice, and Brink will reward you with bonus XP.

Splash Damage point to these cutscenes as evidence that Brink has all the qualities you'd expect of a story-driven triple-A shooter: character, back story, plot and set pieces. Everything has been thought out, accounted for and explained, so that Brink's "maps", for want of a better term, are more than just kill zones. The Reactor, for example, is a case in point. As a nuclear station it was never part of the Ark's green vision of the future. But when refugees started arriving in 2025 - initially in their hundreds and then in their tens of thousands - power became a sought-after commodity. So, a fusion fission reactor was built - an embarrassment exiled to a footpath that extends a mile out to sea away from the main body of the city.

Clearly, Brink is different. It's a single-player, multiplayer, co-op, offline and online shooter all rolled into one. It's an objective-based frag fest in which the objectives keep changing. It's eight versus eight but you're never sure who you're playing with, or against. This is Brink's greatest strength, but in many ways it is its greatest challenge: convincing those who are intimidated by the unforgiving sea of competitive multiplayer shooting that, despite how cold the water looks, the temperature is invitingly warm. "What we're trying to do with Brink is create something that newbies can get into, that they can have fun playing," Paul says as his presentation nears its end. Today, Brink has taken its most significant step forward in this regard, convincing me that it has all it takes to be not only more than just a collection of clever ideas, but truly innovative.

Brink is due out on Xbox 360, PS3 and PC this autumn.