Sam Fisher is back on N-Gage but this time, instead of skulking in sheepishly as a 2D side scroller, Sam busts down the door brandishing fully 3D environments and characters, to bring true stealth action into the palm of your hand. I'm very excited to be reviewing Tom Clancy's Splinter Cell: Chaos Theory!

When you first boot up Chaos Theory, you are treated to a short FMV intro - exciting stuff. The menu offers you the options to start a new single player game, multiplayer game or connect to the N-Gage Arena. It is vital to run through the training level first of all, to become accustomed to Sam's acrobatics and the keypad layout. In a nutshell, 7 is the action key, the * key allows you to select an object/weapon, 1 is to draw your currently selected weapon and 5 is to jump/shoot. Keys 2, 4,6 and 8 control the camera. I do appreciate this control layout; it isn't the best for all out armed combat but that isn't the aim of this game - when caught by the guards, you usually end up being shot to pieces in seconds!

With the introduction of full 3D environments we finally have full stealth on the N-Gage; sneaking around corners, hiding behind walls or boxes, skulking in dark corners and even hanging overhead from a pipe. Sam uses his surroundings to his advantage whenever possible; for instance, you can use two walls to advance upwards by performing split jumps or climb pipes, poles and ladders, all moves akin to the console versions.

And on the subject of the console versions, well, talk about evolution; this is a whole world away from the first instalment of Splinter Cell on the N-Gage. I take my hat off to Gameloft for this one - it's not only extremely similar to the console versions but it's even optimised and improved for handheld. Pretty much all of Sam's moves are intact, along with the light and shade meter that you use to gauge how easily the guards will detect you, plus the use of different goggle modes; thermal imaging and night vision remain intact, both being just plain awesome to look at as well as coming in very useful too!

One of the best things about Chaos Theory is the way the missions vary so much. You are briefed at the beginning while you wait for the game to load (incredibly quickly!) The first mission is infiltration and assassination; you must gather information about one particularly bad egg, by hacking numerous computers and interrogating goons along your way, then track him down. But, alas, you are too late and your only other option is to pick him off from a distance, followed by a dramatic cut scene. This is a refreshing change from sneaking, neck breaking and sneaking some more and an example of how the mission objectives change and throw up surprises once you're in the field - you truly never know what's going to happen next!

Along the way, you will encounter numerous obstacles that hinder your path. Security cameras appear regularly and you can pick up sticky cams to shoot at them, which disables the camera, giving you 15 seconds to dash past. Or you could throw a smoke bomb to get past cameras and guards, which fills the area with thick smoke, allowing you to sneak through. But if you want to be truly undetected, sticking to the shaded areas and walking slowly always does the trick. The shaded areas are not hard to locate; hug close to walls or corners and you should stay in darkness throughout most of the game. The light and shade gauge is an integral part of the gameplay and hugely useful, so keep a keen eye on it.

It's not just about sneaking however, as Sam is equipped with a five-seven silenced pistol and short blade as standard, picking up other weapons along the way, such as the SC-20K assault rifle. All of these are useful in different situations and sometimes killing can be the best approach. Aside from weapons, Sam can use other techniques to maim his enemies, one such technique being the neck breaker. You can do this from behind an enemy by grabbing him and pressing the 5 key - be sure not to hit 7 by mistake though or you'll use your knife to cut him a second smile!

Enemy AI isn't fantastically sharp but it's there. Once you are in darkness, even semi darkness, the guards can't see you, even when you are directly in front of them. I guess this is similar to the console versions, so I can't really complain, but it does seem a little unrealistic. Other than that, the enemy reacts to sound, lights and movement as convincingly as a real person. Adding in that this is all in a tiny mobile game, this is quite an impressive feat. Every enemy poses a threat, as if spotted you can be killed quite quickly or you may set off the alarms one time too many and receive the 'mission failed' message. You must learn to evade them or take them out, using the neck breaker or the blade for a silent kill. From a distance you can pick them off with the rifle and then dispose of the body in a dark corner area. When indoors, try turning off a light switch or cutting the power from a panel and the enemy nearest will come running, attempting to switch the lights on again. This is often a great way to nab one and take him out in darkness.

One truly cool thing about this title is how closely Gameloft worked with the console team. An awfully large amount of work and effort went into making this game as good as it could possibly be on a handheld. Sam's animation and motion is taken from the Xbox/PS2 versions of Chaos Theory and the artwork team did all of the N-Gage media design for the game. This is high profile stuff and sets a benchmark for the quality of future N-Gage titles.

On the N-Gage Arena, you can upload your scores and fastest times on each level, then compare them to other players' scores, and try to beat them. Simply choose your desired level, then choose a player from the ranks, then the game downloads their 'shadow' for you to view and compete against.

Computers and communication of data play a large part in the game, hence you will find yourself hacking a lot of laptops and computers on the way. Sam stores the information and if you take some time out to pause the game and have a look through the emails, you may come across some secret codes. On one occasion, there were cheat codes for Ghost Recon Jungle Storm, another N-Gage game, in an email! Now that's dedication to a platform! Also, it is possible to locate different costumes if you work hard enough to find them, which is another nice bonus.

Let's talk lifespan. There are two sides to this. On one hand, there are about 10 or so levels in the game, each taking on average of at least an hour to complete - at least! So it will most likely take new players significantly longer to pass each stage. On the downside, the levels are restricting in the linear sense. There really isn't an option to choose your own path through a level, which can shorten the life of the game from a replay value standpoint. There's always multiplayer mode, which was a surprise to fans of the series when Gameloft decided to include the fantastic Spy vs. Mercenary mode in the game, where you can pit yourself against another friend or team up in twos and battle as a team via wireless Bluetooth technology. The difference in available moves, weapons and technology between the Spies and Mercenaries, combined with some fantastic level design, makes for incredibly tense and exciting gameplay; without doubt this is one of the strongest multiplayer modes on the N-Gage.

Chaos Theory is a real stunner in the looks department; most of the levels are dark and murky, while some very nice texture work combined with excellent use of light and shade means everything is pretty lifelike. Nice little touches exist in the form of paintings, furniture and televisions through different locations; I often found myself stopping to take a look around at my surroundings, this game has that effect on you. A lot of these objects are interactive also and play a part in the level, so don't overlook anything. Gameloft enhanced the Ghost Recon: Jungle Storm 3D engine for Chaos Theory. This was a great game engine to begin with and provides the fluid 3D motion throughout the game. A little slowdown in frame rate is evident from time to time, but otherwise it runs smoothly and for the amount they're putting on screen, it's more than acceptable.

The sound is amazing, it's atmospheric to say the least, perfect for creating the tension that this game is filled. It gives the feeling that something, anything could happen, so stay alert. The background soundtrack reacts to what's going on in the level, so dramatic music replaces the calm but edgy standard theme when an enemy is sniffing you out or an alarm is raised.

Tom Clancy's Splinter Cell: Chaos Theory is another high quality production from Gameloft, following their successes with Ghost Recon: Jungle Storm and Asphalt: Urban GT. It comes close to being awarded a perfect ten out of ten but falls slightly short in certain places. Still, with amazing and atmospheric graphics and sound, full 3D action, tense gameplay and a host of weapons and gadgets to help you complete a range of missions, this is certainly another must own for the N-Gage. Add to this the awesome Spy Vs Mercenaries mode and I suggest you infiltrate your wallet and pick this baby up!

Reviewed by Dan Whelan for AceGamez (All Rights Reserved).