You’ve probably already seen the COD4 clip that was shown at the Microsoft E3 Press Conference (if not, head over here and get ready to do battle in the radioactive streets of Chernobyl). So we’re going to take you on a wild ride through a handful of levels that weren’t shown during the event, and which we were lucky enough to see during today’s demonstration.

The first mission had the rather dull name of Bog A - thankfully there was nothing dull about what we witnessed. The level kicked off with a squad of US Marines standing on a highway, heading in to the heart of a Middle Eastern suburb to rescue a trapped M1A1 Abrams tank.

The loading screen flashed up satellite imagery of the level before zooming into the battle. To the right of the squad stood a multi-story building, teeming with enemies. The flash of their rifle fire and tracers lit up the night sky as our squad took cover behind the hulking car wrecks that littered the road. As our fellow soldiers scrabbled behind cover, we noticed one of the most impressive new effects in the game - character animation. The bosses at Infinity Ward need to give their animators and engine programmers a fat bonus cheque, as the animation is second to none. We can’t recall any other game where the running, sliding, even stumbling, of the characters looked so real.

The ensuing firefight also showed off the amazing weapon effects, both visually and aurally. The Call of Duty sound guys have always been renowned for their awesome sound effects, and COD4 is no exception. The meaty bite of US M4 rifle contrasted perfectly with the harsh AK fire that our enemies were laying down, while bullets zinged and pinged all around. Clouds of dust erupted from the streaking tracer fire, while RPGs left lingering smoke trails to slowly dissipate in the still night air.

After clearing out the building, we entered into the darkened hallways, flicking on our night-vision goggles to get a clearer picture of the threat within. Doing so allowed us to see the infra-red targeting lasers that were emitted from every friendly rifle in the area. Judging by the number of laser beams penetrating the air, we had dozens of friendlies covering the windows. As we rounded a corner, a hostile grappled with one of our squadmates. Waiting for the right moment, he was soon put down with a double shot to the face. This up close kill revealed even more impressive death animations, which appear to be a mixture of rag-doll and hand-crafted animations.