Throw in some exceptional enemy AI and a few neat tricks, including this year's cardboard box - the oil drum - and you have probably the most fluid and enjoyable sneaking experience I've ever come across. It's perhaps frustrating that Snake doesn't have all the acrobatic manoeuvres of a Sam Fisher or an Altair of Assassin's Creed fame. There will be occasions when you'll wonder why he can't simply climb that wall or hoist himself onto a balcony, like any true super-spy would. All the same, the thin line between giving you enough threats to raise the tension and not being so unforgiving as to spoil the fun is better trod here than in any of Snake's rivals' games. Or MGS3, for that matter.
There's some room to complain about the action, too. After all these years Snake still doesn't feel quite fast enough with a gun in his hand, and this is only more noticeable after the responsive duck and cover systems of Gears of War and Uncharted. Has that stopped MGS4 containing at least one, if not two, of the most exhilarating action sequences I've played this year? Not one bit. The combination of the music, the pacing, the awesome smorgasbord of available weaponry, the enemy AI, the level design and all the cinematic gloss can be fantastically exciting.
And that's before we even get to the boss battles. These were the undoubted high points of MGS3, with the epic, multi-scene sniper confrontation against The End arguably the best of the series. MGS4 might not top that, but it certainly has some masterful efforts. The bosses, mostly drawn from the Beauty and the Beast squad - a group of battle-traumatised woman soldiers with bio-mechanical bestial identities - are as weird, idiosyncratic and challenging as just about anything the series has thrown in before. Just the first fight - a super-charged hide and seek confrontation - knocks any other boss battle I've had this year into a cocked hat. Again, it's all about how cleverly Hideo Kojima can orchestrate suspense and tension. As they used to say about another author's even more famous spy, nobody does it better.
What's more, MGS4 really does give you an unbeatable sense of the way your story is taking place in a wider battlefield, as private military and insurgent forces clash, and the rattle of gunfire reverberates through the streets all around you. The effect is primarily atmospheric, but the conflict has its gameplay implications too. Your loyal sidekick, Otacon, recommends early on that you avoid getting involved in the fighting, and he's not always wrong. Start causing trouble yourself, and you're more likely to bring additional troops and tanks onto the scene, making things more difficult for you. However, there are also times when stirring up the ants can provide you with the distraction you need to get to the next objective. In either case, the way the AI, the visuals and the audio continually work together make this war-torn world a hugely convincing place.