Though the Syphon Filter games are, aside from one or two exceptions, popular, critically acclaimed and lucrative, they have never quite met with the success they have deserved. Talk to many gamers and they will remember the PSone iterations with a fond sigh and a sparkle in their eye, but glance at any top-ten list and they are unlikely to feature.

Though any substantial stealth elements to the adventures of Gabe Logan and his associates are minimal, there is a degree of truth to the fact that Syphon Filter was a little overshadowed when it first appeared in 1999 by the storm of hype that surrounded the year's big hit, Metal Gear Solid. Though the gameplay maybe different, both were high-tech thrillers with intricate plots and gruff anti-hero protagonists. Logan just lost out to Snake, and has been a little on the back foot ever since.

Still, Syphon Filter: Dark Mirror is one of the PSP's greatest titles, and I was lucky enough to have extensive access to the current preview build of its sequel; Logan's Shadow. To a certain extent, it does fall into the 'more of the same' category, but it is still filled with a substantial handful of new gameplay elements, a noticeable improvement in script and character, and looks set to improve on one of the PSP's best third-person action games.

For now, the opening to the training stages is largely similar to Dark Mirror. You quickly learn the instinctive control system, which easily negates the handheld's lack of a right analogue stick, by giving its functions to the facia buttons. Using the Left stick and X, square, circle and triangle buttons works surprisingly well as a replacement for dual stick control, and Sony's Bend studio have done an incredible job of assigning the rest of the controls to the d-pad and two shoulder buttons.

As you progress through the training, you are introduced to the game's new features, including a swimming system that lets you fire through and from the secluded depths of various watery areas. Under the water's surface you can move nimbly through 360 degrees, using new weapons such as the spear gun and bolt pistol, or struggle with the reduced firing rate and bullet speed of your normal weapons, adding a wonderful new dimension to the gunplay and combat.

Perhaps inspired by the likes of Gears of War and the console-based craze for hide-and-move tactical shooters, Logan's Shadow features an updated cover system that allows for blind firing to pin enemies, and the option of taking human shields. Fear not though, for while still a game of skill, the new Syphon Filter sticks faithfully to its roots, unconcerned by the need to include the likes of squad-based play and overwhelming strategic forethought.

Instead, it is a classically styled third-person-shooter that is fast paced and considered in equal measure. Quickly you will be methodically pushing your way through intricate networks of corridors, rooms and open industrial areas, racking up headshots and leaning round corners to take aim with precision and speed, giving you the hugely satisfying sense that you are the kind of quick-shot who could easily pick off an ace from a shower of falling playing cards.

In addition to developments in the combat, there is a new focus on quick time events, which require the player to press buttons in time to on-screen commands. In the game's opening level they seemed most commonplace, and featured when Gabe's helicopter support dropped in at various times, to clear debris from the deck of a large ship the butch hero was exploring. At certain moments combinations of the facia buttons had to be pressed to unlock and operate the helicopter's grabber. Applied to using gadgets and machines, the QTE elements seemed unobtrusive, compared to other games such as Broken Sword: The Sleeping Dragon, where their use seemed a little random.

Moving onto plot, previous Syphon Filter games have always been defined by intricate stories filled with politics, terrorism, subterfuge, and double-crossing officials. Logan's Shadow again returns to these clandestine themes, but whereas before they were confusing to the point where you might choose to ignore them, this time there is a marked improvement in both the storytelling and scripting.

It's shaping up to be the perfect sequel

This is most likely to the credit of Greg Rucka, a veteran comic book writer who has handled the mighty Batman, Gotham Central and Queen and Country, and written the story of Logan's Shadow. The plot sees you in pursuit of an extremist terrorist group on the run with some devastating stolen government technology.

The scripting is surprisingly witty, refreshingly sharp, and filled with a marked increase in volume of bad language, giving it the feel of an adult graphic novel. Gabe is joined again by his old accomplice Teresa, and faced with the realisation that his closest colleague, Lian Xing, maybe a traitor. For fans of the series that remember how believable the relationships between the game's main characters have always been, the appearance of such developed and memorable faces will be a pleasure to behold.

Of course, with such an early build of the game to play with, some bugs and glitches were present, but with a late autumn release pencilled in, and the game in general looking superb, there is little doubt that Logan's Shadow will be a very tidy, smooth piece of software.

With the multiplayer, buddy system and brand new mini-games to test, Logan's Shadow still has plenty to prove, but it is already looking like Bend, who developed Dark Mirror, have produced another diamond in the PSP's decidedly rough crown. Look for more on Logan's Shadow in the coming months.