Combat is visceral and unrivaled. You've never experienced anything more vicious and unforgiving. Rockets zip past your head, attack choppers shred nearby houses with gunfire, jets carpet bomb an area, tanks blast through walls and soldiers fall by the hundreds. The insanity, coupled with your character's inability to absorb as may hits as in other games (Halo 3, Bioshock), causes you to question your actions and rethink strategies. Bottom line, if this game represents even just a fraction of the hell actual soldiers deal with on a day-to-day basis, we have a newfound respect for the armed forces.

Although Call of Duty 4's single player campaign takes less than ten hours to complete, it features excellent pacing and a solid conclusion. You'll want more, but that's only because the game's so amazing, but there's other things to enjoy including the now unlocked Arcade Mode, where you complete missions (in order or out of sequence) to rack up points with each kill. Point totals vary depending upon the action, so getting head-shots or melee kills (a wicked knife slash) earn more than just shooting someone's chest. Upon completion, you can upload your high scores to the online leader boards and compare them to the rest of the worlds'. It's a simple mode, but it adds several hours of replay value. Of course, then you have the multiplayer to deal with.

Modern Warfare's multiplayer campaign is a game all its own, a beast with so much depth that you'll play it well into next year. At its core lies the usual assortment of modes, such as Team Deathmatch, Free-For-All (every person for him or herself) and Sabotage (grab a bomb and destroy the enemy base), among others. But developer Infinity Ward makes things interesting by locking away much of the game. This includes many of the weapons, equipment (scopes, grenade launchers), perks and play modes. To unlock them, you must level up, by earning experience points through playing games and getting promoted. Each rank (Private, Colonel, Gunnery Sergeant, etc.) has levels, and the more you play/kill people, the more goodies you uncover, which in turn allows you to branch away from the game's five primary classes (Assault, Spec Ops, Heavy Gunner, Demolition, Sniper) and create your own, choosing your soldier's primary weapon, side arm, special grenade and the aforementioned perks, which give you a battlefield boost. Last Stand, for example, enables you to fire off some extra shots before dying. Sonic Boom, on the other hand, gives you higher explosive damage, while Deep Impact increases bullet damage. With that said, it's best to play well and often, lest you encounter high ranked players that'll quickly put your brains into the nearest flower patch.