Yet while unquestionably excellent and powerfully addictive, Left 4 Dead never becomes intoxicating to the point that you realise you haven't eaten all day and you've got a review due tomorrow. A single ninety minute campaign is generally enough to slake your thirst for blasting zombies -- for a few hours at least -- and should be easy enough to organise between a group of friends.

And friends are what you're really going to need if you want to get the very best out of Left 4 Dead. Playing with the bots the game is a shadow of its potential greatness and the higher difficulty settings will remain strictly off limits, but get three friends together with microphones and Left 4 Dead is possibly the best multiplayer game ever -- not something that we say lightly.

Tactics are hastily arranged, cries for help as boss infected attack are screamed down mics, panic sets in and heart rates rise as wave after wave of zombies appear. The palpable feeling of accomplishment you get after finishing a tough campaign together is something that no other game can offer.

It's fair to say you can judge a game by its "remember the bit where" factor. You're talking to friends about a favourite game, when a memory of a particularly awesome moment you've shared pops out and reminds you all just how great that game was. Left 4 Dead is full of such moments. It's an ever changing, ever challenging and ever tense multiplayer masterpiece which will captivate for as long as you've got friends to play it with.