It certainly helps that the game starts on such a strong point. The first mission – a raid on a terrorist cell based in a derelict Peruvian lighthouse – is just brilliant, with more dramatic moments and tense choke points than you have a right to expect from one level. Just as importantly, it also shows off a graphics engine that’s a match for just about anything you might mention, with the sort of detailed background textures and lifelike models that make the game world almost tangible. And while Splinter Cell has always led the way with lighting, Chaos Theory has possibly the best I’ve seen in any game, not to mention some cool weather effects. The Xbox version looks superb. The PC version is just spectacular.

And while succeeding levels have trouble matching the opening for sheer impact, each brings its own pleasures, often in the little surface details that bring each environment to life: the personal effects that litter the crew’s quarters on a cargo ship, the folded towels in a shady millionaire’s penthouse. Realism for realism’s sake means nothing, but here it helps give you that feeling that you’re engaged in the world’s biggest game of hide-and-seek. As Sam creeps through the corridors of a South American bank, two guards chatting in a glass security cube stage right, it’s hard to keep your heart out of your mouth.

Particularly when, this time around, the guard AI is near perfect. Many espionage games veer too far towards either blanket stupidity or supernatural perception, but Chaos Theory does neither. Guards will notice sudden movements and loud noises – and they’ll definitely spot a nearby colleague lying down on the job with a bullet in the head. But, that doesn’t mean they’ll clock you slinking through the shadows, or that they won’t forget a quick glimpse if you hide yourself quickly. If roused, they will pursue you, but they won’t go out of their way to hunt you down.

As a result, Chaos Theory always delivers enough tension to make you sweat, but not so much grief as to make you weep. Even the audio plays a part here, with Amon Tobin’s soundtrack playing low at times of quiet concentration, then kicking in with the big drum n’ bass themes when you sound an alarm or start off a firefight. The spot effects work brilliantly, and hiring Michael Ironside to voice Fisher sounds even more like a masterstroke this time around, proving how much more interesting a character becomes if you can just get the right actor onboard.

So as a single-player game, it’s fair to say that Chaos Theory is simply phenomenal. However, lucky PC, PS2 and Xbox gamers also benefit from two multiplayer modes, one a competitive agents vs mercenaries option, the other a brand new cooperative mode. This has two agents joining up to work through four specially designed missions, structured to encourage teamwork. Players can help each other up and down walls, toss each other across gaps, and try out a mass of other co-op special moves. It all makes for a nice spin on the action.

Add this to the single player component, and you have one of the most impressive game packages this year. In fact, Chaos Theory is pretty hard to fault. Okay, so at heart it’s really a refinement rather than a revolution, but when a game is this slick, this polished, and this much fun, who are we to start complaining?

Verdict

Splinter Cell finally loosens up and has some fun, with a game that has all of the strengths of previous titles but none of their drawbacks. The state of the art in espionage action.