On the first day of PAX 2011, a confident booth in the middle of the convention's show floor claims to boast the longest queues of the show, and it's for a downloadable game rather than a mammoth AAA title. Isn't that a bit daunting for the staff manning its 10 demo stations? Apparently not - they say it's exciting. I'm inclined to agree: excitement is the right response when the developer is Valve, and when the game in question is Counter-Strike: Global Offensive.

It's hard to overemphasise just how significant Counter-Strike has been, but it's safe to say that all modern multiplayer shooters owe it a debt. For me, it was the shooter that got me into online gaming - I simply adored Counter-Strike at the turn of the millennium. I remember the agonising wait between getting home from school and the off-peak phone services kicking in; I remember my buy-scripts and bunny hopping, custom config files, and asking my mother for an ISDN line for my birthday so I wouldn't have to play with a useless 56k modem. As for the game, I even remember when the M4A1 had a scope.

The world is different now, of course, and since Counter-Strike hit 1.0 in the year 2000 we've seen the console become a viable platform for the genre and the rise of always-on broadband connections in the home. Provided your housemate isn't a copious pornography hound or BT aren't having a funny five minutes, you no longer need to fiddle with your cl_updaterate.

Valve's problem with Counter-Strike, then, has nothing to do with publisher or platform (it's being released digitally for Xbox Live Arcade, PlayStation Network, and Steam), but instead lies with deciding what to do with the mechanics of this cherished property, and proving to the world that there's room for Counter-Strike in 2012. But Valve has resisted throwing in traditional modern features for the sake of falling in line with the game's contemporaries.

It's telling, for instance, that there's been no addition of iron sights - the ubiquitous calling card of any shooter released this generation. Make no mistake, Counter-Strike: Global Offensive is an absolutely vintage interpretation of the first-person shooter, mapped competently to a controller. On the 360 pad, the right bumper cycles through your weapons - primary and secondary weapons, and then the knife - with the left switching through your grenades. Yes, you still run faster with the knife equipped.

Rather than relying on analogue sticks to control speed, you use a dedicated button to toggle between walk and run states. You'll need to use it, too; weapons thrash like a mule and require careful burst firing, and plenty of new players will be thrown off by the degree of competence demanded by the unchanged arsenal.

While the veterans will feel right at home, even on a controller, one of Valve's biggest priorities is actually making Counter-Strike appeal to new players - players who've never even argued about which is the better map between de_cbbl or cs_italy. To accommodate for beginners, then, the game will include skill-based matchmaking, surrounding you with people at a similar level of play.

The biggest difference between Global Offensive and the Counter-Strike of old is that the teams are fixed to five versus five. It's a far cry from the 24-player servers I remember growing up with, but a setup that perfectly suits for competitive play.

The rest, however, is business as usual. Depending on gametype, two teams of terrorists and counter-terrorists are out to either detonate/defuse a bomb or hold/rescue a group of hostages. Players are awarded cash for kills and for completing the objective, and at the start of each round that currency can be used to buy weapons, equipment and ammunition.

The map on show is de_dust (how could it have ever been anything else?) and it's exactly how your mind's eye remembers it. Dust, for those that have never played it, is a blissfully intelligent creation, easily the most conceptually perfect multiplayer construction of all time; a map which neatly and competently nudges you into confrontation in the most perfect of spots.

But, after a few rounds, you start to realise things are a little bit different. I'm not simply talking about the visuals (thanks to the joy of modern technology you can actually make out the dust now) but in some fundamental changes to the construction. There's now a staircase leading up from the underpass, as well as additional cover along the way, allowing terrorists generally safer transit and the option to nip away from confrontation if they get ambushed.

There's slightly more telemetry on the level, too, making it marginally less daunting to navigate around if you don't have the locations for bomb sites A and B permanently etched into your memory.

On top of this are new weapons and grenades, most notably the Molotov cocktail which can easily cut off entire areas if thrown in the right spot - such as the doorway near bomb site A. There are also Decoy grenades, which explode into sounds of gunshots and provide the perfect bait for hasty enemies looking for some cheap kills.

Another highlight is the Zeus, an inordinately expensive taser that's a complete bugger to fire but a guaranteed one-hit kill. It's a comedy weapon, basically. And while we're on the subject of money, the game will include two modes, one of which is far more generous at handing out money than Counter-Strike has been in the past.

Valve will only confirm de_dust at present, but from the trailer I can distinctly make out de_dust2, de_aztec, cs_office, and cs_italy. Eight new maps are promised, alongside seven returning classics. Fingers crossed for de_cbble, everyone.

Counter-Strike, then. It feels like it's never really been away, but I certainly can't wait to have it back.

Counter-Strike: Global Offensive will be released for Xbox 360, PS3 and PC in 2012.