Mirror's Edge

"Basically, when you move through this game very fast, we wanted the player to be able to understand very quickly when or where they could go or should go," says O'Brien. "The way I often describe it is that Jason Bourne sees the world differently to everyone else - he sees weapons where you see a pen - so in this case [the game] shows us a route...and this happens dynamically throughout."

In practice what you see is an object glowing bright red against the game's largely white and cool-blue palette (one of the first screenshots illustrates the concept). If there's a door you're meant to go through, it will turn red as you approach it, and then you can adjust your sprint or flight through the air to land and smash through it smoothly. It also highlights things like cranes and pipes suspended between buildings. Elsewhere, the other big problem with free-running is snagging, and although O'Brien didn't address it he didn't really need to - we saw no evidence of problems, although it will take a hands-on session to render any kind of judgement on that front.

Runner Vision - "TM!" jokes O'Brien - will need to be employed as guidance rather than a crutch for dumb players, but DICE seems to get this. The one puzzle we're shown is a simple movement puzzle in a cramped hallway, where Faith has to try and reach a highlighted vent near the ceiling, and the challenge is working out how to combine the various ledges and footholds around the room to get to the top rather than trying to work out where to go. O'Brien says to expect more complex puzzles later on, suggesting that for all the movement and momentum chatter the developer has worked to vary the pace.

As if to ram the point home, as soon as Faith drops out of the vent she's set upon by cops, who start chasing her. At this point the music goes a bit Half-Life 2, reminding us of Gordon Freeman's own flight across rooftops, and the player has to combine various manoeuvres quickly and effectively - using Runner Vision to guide Faith - to outpace her pursuers. As she takes the odd bullet, the colour starts to de-saturate to illustrate the loss of health. "We wanted to keep a very clean-looking game," says O'Brien, as we notice there's sod-all else on the screen. At the end of the chase, Faith has no choice but to tackle a pair of cops head on, doing something clever with her hands to disarm them and profiting to the tune of a gun. So guns do exist, but they're "kind of a temporary power-up", says O'Brien, lasting for as long as there are bullets in the clip, but slowing you down. You wouldn't be much good at parkour if you had an assault rifle on your back, after all.

Getting away from the rest of the cops involves breaking line of sight, says O'Brien, but in the meantime Faith has a bigger problem, which is that she's running out of rooftop. Fortunately there's a news helicopter swooping past. This gives our minders a chance to show off Reaction Time - "basically our version of Bullet Time" - which is accumulated by stringing together slick moves. It's used to slow down time and fine-tune big jumps, of which this is one, leaping Faith from roof edge to helicopter skid at the end of a sequence of ducks, dips and dives.

It's just one level of a game we probably won't get to play for some months, but it's bright and interesting, even if you do have a radio dispatcher talking into your earpiece called "Merc". The chaps at Electronic Arts hope that Mirror's Edge will be able to play the Assassin's Creed part in this year's hype parade, so look out for more carefully crafted reveals in the months ahead before they, and DICE, will finally let you have Faith.