It debuted as a promising new series in 1999, but with each sequel Sony's first-party Syphon Filter franchise slowly descended into mediocrity. Until now. Full reverse. Stop. No, don't.

Agent Gabe Logan makes his debut on the PlayStation Portable with gusto, delivering in just about every way that counts. Great graphics: check. Compelling story: check. Intuitive controls: check. Addictive multiplayer: check. Winning lotto numbers generator: one can dream.

In short, it's the action game PSP owners have been waiting for, and proof-positive that the PlayStation Portable can deliver a gaming experience every bit as profound and powerful as a triple-A title designed for home consoles.

The story, which begins with Logan investigating terrorist attacks on chemical facilities, is strictly by the numbers, but it's delivered with all the bells and whistles of a Hollywood blockbuster. High quality, action-packed cinemas pop up regularly between missions, providing both drama and thrills, and a surprising amount of spoken dialogue plays throughout each mission as Logan chats with his support crew and listens in on enemy conversations.

More impressive are the controls, which, for the first time in a PSP shooter, actually feel comfortable. The analogue stick is responsible for movement while the symbol buttons on the right are used to look around. It's not quite as comfortable as a pair of analogue joysticks, but it's not far off. The controls for specific actions, such as choosing vision enhancing goggles, selecting weapons, and performing context sensitive actions like jumping onto a zip line or hopping over a crate, are a little less instinctive, but a series of five training missions at the beginning of the game helps players get a feel for things relatively quickly.

But the real reason to check out Dark Mirror is gameplay, which holds little in common with previous entries in the franchise. In fact, if it weren't for all the firefights it would feel a lot like Splinter Cell. Logan is all about the stealth kill when possible, sneaking up behind enemies to snap their necks and using his knife to silently gut his foes. He also has some Sam "Splinter" Fisher-esque gadgetry, including electric shock darts, gas darts, and explosive darts. There are times when the only course of action is a full on frontal attack, but even then the best strategy is usually to hide behind environmental objects, peek around corners, and fire from cover.

Stretched over seven chapters composed of several missions each, Dark Mirror is a surprisingly long-lasting play, but when you take into account the local area network and online multi-player modes -- easily the best of their kind for the PSP -- its value rockets through the roof… or it least it would have had Sony seen fit to include more than a handful of multi-player maps. Thankfully, the deathmatch and objective-based levels that do exist are large and take a while to master, giving players a chance to experiment with all of the game's online extras, which include voice chat, scoreboards, and even clan support.

The short version: Syphon Filter: Dark Mirror is just about the best thing going on the PSP, especially if the combination of stealth and action turns your crank. You can pull out your wallet with confidence.