Let me explain. As in previous instalments, you're still playing as a soldier within a small squad, following orders and working through each level along a fairly linear path. In fact - barring a few isolated sections - CoD4 is actually more restrictive than CoD3 in this respect. Your job isn't to be a one-man army as it is in most FPS games, but to do your bit to eliminate the opposing forces and enable the squad to keep pushing through towards the next objective. Sometimes this means being the first one through the breach, sometimes this means hanging back and providing fire support and sometimes this just means standing your ground and blasting each and every bad guy that comes your way. Where CoD4 most differs is in the pace. It's much more about moving fast, reacting quickly and taking the enemy by surprise than even the fairly ferociously paced CoD2. At times it's an amazingly frenetic experience.
In actual fact, the game delivers several twists along this same basic theme. The plot intertwines a coup in a middle-eastern state with dodgy nuclear activities in Russia, with the former featuring a US Marines operative and the latter starring a new recruit to an elite SAS unit. The Russian stages are generally faster moving and more fluid, while the middle-eastern stages feature more concentrated, large-scale battles. On top of this, the game throws in a couple of air-support shooting gallery sequences and a duo of ‘flashback' levels that are probably the finest stealth and sniping levels I have ever seen in an FPS game. If monotony of setting and game style was a huge problem for CoD3, it's never an issue in CoD4.
More importantly, the game rarely falters or loses focus when it comes to dishing out the action or the spectacle. The opening on a storm-blasted Russian freighter is dazzling, with superb moody lighting, awesome weather effects and a constantly pitching, shifting environment that threatens to bring on nausea at times, yet the game follows it with scenes of shock and awe that even Michael Bay might think excessive. There's not much in the way of emergent enemy behaviour - die and you'll watch the same goons go through roughly the same motions all over again from your last checkpoint - but through smart use of cover and sheer weight of numbers they constantly provide a satisfying challenge. There's a thrilling selection of long-range and high-powered weaponry to blast them with, while techno toys like night vision, anti-personnel mines and guided missile launchers give the game a meaty modern edge.