As competitive gamers we all strive to succeed, but every once in a while things can go too smoothly. Ubisoft's January showcase for Future Soldier provided ample opportunity to check out the game's SyncShot mechanic - a powerful manoeuvre that involves all four members of the player's squad taking down an enemy at the same time. You designate targets for the AI, wait until everyone has a clear line of sight, and then give the order. Hey presto, a quartet of dead tangos. There's not even a BANG, thanks to the fact you're all using silenced weapons.

The only problem with SyncShot in the single-player experience was this: it was almost too effective. AI-controlled allies aren't exactly in the habit of missing their headshots, after all, and at times it seemed almost effortless to clear a camp of its armed guards. It almost seemed too effective: Very empowering, yes. But challenging? Less so.

Two months on, trying the game in co-op for the first time at the studios of Ubisoft Paris, Future Soldier is a different experience. Once again the fifth mission of the campaign is an early highlight of the demo - this is one of the first assignments where the game really lets you off the leash - but now there's a palpable sense of tension that was barely felt in the new year. It's one thing to sneak-and-snipe your way through a base with the help of three perfect killers, but when you're in the company of the three other equally error-prone humans, there's a far greater likelihood that everything could go wrong at the drop of a hat.

There's a near constant back-and-forth flurry of chatter over headsets as each individual reports on what they see, on where they're going, on who's in their iron sights. One player is designated squad leader, but this is very much a group effort. You have to work that much harder, and the pay-off is a far greater sense of achievement. When the four of you wriggle into position, mark your victims, and then pull off a successful SyncShot, you feel like you've earned it.

It becomes apparent, too, that in later mission the SyncShot isn't the all-conquering super-weapon it first appears to be. In any situation where you're faced with more than four threats, for example, a new set of tactics come into play. Either you can carefully time your efforts so as to eliminate guards while they're out of sight from their comrades, or you can try to extend the effectiveness of the initial Syncshot. Provided that everyone scores a perfect headshot at roughly the same moment, time slows down for a precious two-second window. Make the most of this, and each squad member can score an extra kill - theoretically allowing you to wipe out eight or more foes at a time.

Again, clear communication is essential if you're to pull off a stunt like this, especially if your current task forbids you from alerting the OpFor. One of the later missions in the campaign finds the team conducting a nocturnal assault upon a hostile airfield - a setup that takes a zero tolerance approach to enemy attention, combined with a tricky open environment. There's almost a puzzle-like feel as you cast scope in on foot patrols and elevated snipers, weighing the sequence of executions.

Also on show at Ubi's latest demo was Guerrilla mode - the now-mandatory riff on Horde. As per usual you're squaring off against increasingly tricky waves of foes, and as per usual it's swiftly engaging, despite the familiar setup. Future Soldier's main spin on convention is that you're here tasked with defending a marked-off area of the map, with failure arriving swiftly if an enemy reaches the hallowed ground. It's possible to use stealth to get the drop on the approaching foes, but this quiet approach rarely lasts long. There are also shades of Modern Warfare 3's Survival mode here: explosive weapons like Claymores and grenade launchers become increasingly important as the waves get tougher (which doesn't take long), and there are support powers you can call in to temporarily level the playing field: the Ghosts' cloaking devices are relegated to this cameo role, but then the mode would be far too easy if that weren't the case.

And if nothing else, this latest showing proves that Future Soldier won't be a cakewalk. Guerrilla is an unexpected bonus, but the most pleasing development is certainly the fact that co-op seems to work so well. Indeed, this feels like a game that's been built from the ground up with multiple participants in mind; its greatest assets are the pockets of tension that crop up when the Ghosts are trying something risky, and for that you need to imperfections of real players. For a game so obsessed with cutting edge technology, it seems that human fallibility may be the most important ingredient of all.

Tom Clancy's Ghost Recon: Future Soldier will be released on May 25 on Xbox 360 and PS3. A PC version is also in development.