Call of Duty 4's audio is equally satisfying. Constant radio chatter blares throughout, with Price and fellow soldiers yelling (and sometimes whispering) commands and locations so you don't shoot at the wrong time. Enemy soldiers have their own comments as well, speaking in Russian and Arabic. The sound effects are in a league of their own, with various types of gunfire, speaker-shaking explosions and military vehicles rolling by, either overhead or by your side. Dramatic music also kicks in on occasion, ramping up the intensity during a stage or rewarding you for a job well done.

Call of Duty 4's single-player campaign lasts six to seven hours, with various difficulty levels to choose from (go with Veteran, you pansy), plenty of flashbacks (including one where Price attempts to finish off Zakhaev) and -- best of all -- an unlockable Arcade mode with point building and leader boards. However, the multiplayer component is a separate game on its own, with its levels of complexity and depth. Several modes are on hand, including typical entries such as Deathmatch (Free-For-All) and new ones like Headquarters (capturing a rival team's radio), Domination (a new variation of Capture the Flag) and Sabotage (using bombs to blow up another team's vital objects). These modes will have you playing for days (if not months), if only to discover the subtle differences between each one as you frag your friends. The PlayStation Network should find excellent use here, as the game supports up to eighteen players per match.

What's really remarkable about the multiplayer, though, is the introduction of "perks" and the level-up system. Over the course of combat, you can assign perks to your soldier, enhancing their performance in a number of areas. Some temporarily allow you to see enemy positions on a roving HUD, so you can set up a quick and nasty attack to achieve a few quick frags. Juggernaut, on the other hand, gives you a small life boost . Over the course of the game, you'll level up significantly, improving your performance with multiple classes and better weaponry. And you can expect the usual online staples, such as clan building, the ability to set up private matches and detailed stat tracking.

Unimaginable and lifelike presentation, refined gameplay that follows a tried-and-true formula, a multiplayer mode as in-depth (if not deeper) than the powerful single-player campaign -- and with that, we conclude by saying "wow". Call of Duty 4: Modern Warfare does so much right that it's hard not to give it a ten. It not only sets the standard for Activision's long running franchise, but also for current-gen first-person shooting games in general. Consider it right up near the top -- if not at the top -- of 2007's best games list.