So any major new gameplay features?

Grant Collier: Yeah, in Call of Duty 4 we have the modular nature of modern weaponry. That really allows us to change how the gameplay acts. Now you can have silencers, you can have laser targeting, you can have under-mounted grenade launchers, you can have 2x scope, 4x scope, 6x scope.

All these things allow the weapons to have a lot of different personality depending on which kind of attachments can be on them. That's a huge change.

Also, there's having night-vision on your side. Sometimes the enemy has night-vision, sometimes it doesn't and they're like launching flares and that really affects their visibility.

In the demonstration, I came up and knifed that guy in the dark, and he couldn't see me - and the other enemy with the RPG, his behavior switched to melee rather than using the RPG and I backed up and hosed him down.

Both those things have a huge impact on the gameplay.

Is it still fairly linear with scripting?

Grant Collier: I think a lot of people in the past have knocked us, like "Oh my gosh it's scripted, it's scripted." Every cut-scene that you've ever seen, they are always scripted. There's not a single cut-scene that you'll see that isn't scripted. And we allow the player to play through these cut-scenes.

So I think it's unfair for people to knock us for that because we give them an added benefit where we don't stop the screen, we don't pull you out of the immersion.

We're creating a really immersive, entertaining product where we actually give the player the ability to move through and follow storyline. If we got rid of all that, that would be like getting "What would we do to add cut-scenes back in?" Which is something we don't want to do.

How do you go about creating the intense action sequences?

Grant Collier: I guess this is kind of giving away our secrets, but since no one's been able to recreate it in the past six years I don't think we have much to worry about really.

We try to create that living, breathing battlefield. It's not just the fight between you and one guy, there's all this other shit that's going on around you. You'll see jets flying through the sky, you might see things exploding in the distance, or a rocket truck launching rockets, maybe planes crashing and tanks battling it out.

Plus you have your really life-like squad around you that are doing things that make it feel like you're not alone - they're actually putting down fire, they're telling you where the enemy is, they're giving you orders. And there's a lot of bad guys around, you've got enemies coming at you from all directions.

It's a combination of all those things that really make it. And the immersion level. We want it to be as authentic as possible and we want it to be as realistic as possible.