Of course, while the original Call of Duty was a PC exclusive, Call of Duty 4 is hitting PlayStation 3 and Xbox 360 as well, with apparently no expense spared on any system. "This is true multiplatform development," studio founder Grant Collier stressed during a recent Activision press event. "There's no lead platform here."

You wouldn't think so, with the Xbox 360 the only platform to have gotten access to COD4's multiplayer beta, and publisher Activision showcasing the Xbox 360 version nearly exclusively at events and expos. So it was a change of pace to hear Collier announce that Infinity Ward will be releasing a single-player PC demo this week, with no word yet on an Xbox 360 (or PS3) version.

Collier also announced that fan-favorite composer Harry Gregson-Williams, known for his memorable work on the Metal Gear Solid franchise, has provided the game's musical score. Apparently, one journalist had already correctly identified the unannounced musician based on bits of the game's soundtrack.

After Collier's address, I sat down to play through two missions of the game on PC--where, it must be said, the game and its series still feel most at home.

Don't Rock the Boat
First up was a night raid aboard what seems to be a Russian-controlled cargo ship, played from the perspective of British S.A.S. man "Soap" McTavish. Boarding the vessel on what Snoopy would accurately term a dark and stormy night, the game does a great job of representing the ultra-elite nature of the unit. McTavish represents one of Call of Duty 4's prime protagonists.

From the arrival by helicopter to the quick, stealthy infiltration of the cargo hold, every movement of the small squad feels highly and appropriately controlled. "Rules of engagement, sir?" asks one squad member before the mission begins. "Crew expendible," an officer replies ruefully, with well-done voice acting whose rough British accent gives the response a satisfying edge.

Precise chatter is constantly thrown out among the squad members, driving the fairly simple mission forward--"Corridor clear! Check right!" your squadmates relay in quick, hushed shouts--and providing believable AI teamwork. Sleepy ship crew members on patrol simply don't stand a chance. All the while, the mission is being punctuated by bursts of thunder and lightning which briefly illuminate the scene in stark silhouette.

After apparently reaching and securing the mission target, something goes wrong sooner than expected and the gameplay switches from brisk, tactical play-by-play action to a frantic escape. The gentle rocking of the cargo ship turns to violent lurching, jerking the screen almost sideways at time. It's a satisfying shift.

This is all highly atmospheric and graphically impressive, with the game running at maxed graphical settings throughout. A stealthy dxdiag revealed that the demo machines boasted quad-core Xeon CPUs at 2GHz armed with GeForce 8800GTX video cards and 3GB of RAM. On those machines, I was able to turn the video resolution up to the monitors' native 1900x1200 without suffering negative framerate effects.

War is Hell
"No battle plan survives contact with the enemy," reads a randomly-selected quote by Colin Powell during one of the game's loading screens. It is an apt tone-setter for the other demo mission available during the event, a chaotic firefight in a Middle Eastern capital city befitting of the game's subtitle--based on what reports from conflicts such as Iraq tell us about modern warfare, if there's a gameplan, the parties involved are making it up as they go along.

In stark contrast to the highly-controlled cargo raid, this mission is more wide-open, with you and your squad attempting to secure a pinned-down M1A2 Abrams tank dubbed "War Pig" in the middle of an intense guerrilla firefight. Hostile and friendly gunfire erupts from seemingly every window and doorway of every ruined, crumbling building in the city, and in many cases routes to the next checkpoint are ill-defined.

It is all extremely chaotic. You can never stay in one place too long, lest too many enemies get a bead on your position and rain down grenades (which you can toss back at them if quick enough on the mouse) and heavy fire. The opposition seems essentially limitless, so you must continually avoid staying in one place too long while also ensuring your path is at least free enough of enemy fire to make your next sprint survivable.

There are some particularly great moments, including the use of a computer-assisted fire-and-forget Javelin anti-tank missile system to take out a caravan of enemy armor, and a scene played out in night vision that highlights friendly rifle laser sights, creating a criss-cross of luminescent green lines that looks like something Tom Cruise might have to navigate in Mission: Impossible.

Land Grab
In addition to the two single-player missions, I checked out a multiplayer map not included in the multiplayer beta that recently concluded on Xbox 360. Entitled Ambush, the map is set in a Middle East city reminiscent of the setting of the second single-player mission, though during daytime rather than dusk. Filled with ruined buildings providing plenty of inconspicuous cover, the map is well-suited to tactical play, and was perfect for the territorial control gametype and the Counter-Strike-like bomb-laying (or bomb-defusing) gametype.

As a longtime PC shooter fan, I couldn't help but feel more at home with the PC controls than the dual analog sticks of the Xbox 360 version, though to be fair Infinity Ward has proven it is one of the few developers able to do console FPS controls properly, and the Xbox 360 and PlayStation 3 versions of the game should be extremely playable. Still, it's nice to see Infinity Ward bring the series back to the platform that spawned it.

Infinity Ward's Call of Duty 4: Modern Warfare is set to ship in North America on November 5, 2007, with a European release to follow on November 9. A Nintendo DS version by n-Space should ship simultaneously. Look for a PC demo on FileShack this Thursday.