Think 'Nintendo'. Think 'handheld console'. Think 'sophisticated wargame'. Wait a second, there. It's not such a smooth progression of logic, is it? Sometimes, you have your expectations of a game utterly confounded and turned on their head. Being relatively new to this whole 'owning a handheld console' thing, I wasn't really sure what to expect when I cracked open the cellophane wrapping of the game box.

Sure, I knew Advance Wars: Dual Strike was a turn-based strategy. Sure, I knew that the franchise was very highly regarded. Sure, I knew that it was one of the most eagerly awaited titles on the DS this year. I simply wasn't expecting it to be quite this good. Turn-based strategy is a genre I've been keen on ever since the early days of X-Com and Civilization, but the concept of playing a turn-based strategy on a handheld was quite alien to me. You don't naturally expect the depth or refinement of the game mechanics to be equivalent on a handheld for a genre you expect to more commonly find on the mighty beige tower of a PC. Well, Advance Wars: Dual Strike cheerily cocks a snoot to all that computing power and ably demonstrates how good things can come in small packages.

Given the context, the sheer number of game types on offer at the main title screen is pleasantly surprising. Not only do you have the single player Campaign mode, but also War Room, Versus, Survival and Combat modes. The twenty-eight mission Campaign mode is where you'll probably spend most of your time. The Campaign is very well structured, with a good learning curve. New Commanding Officers (COs) and subtleties in the game mechanics are added consistently and gradually throughout the first dozen or so missions, letting you get used to new unit types and tactical options without ever feeling out of your depth. The campaign story is pretty nominal, in all honesty, though the COs each have discernible personalities; I'm not entirely certain whether the script has been written for laughs, or whether a lot of the humour is unintentional, but the interplay between the COs in the campaign dialogue will be sure to raise a smile or two. So whilst the characterisation may veer towards pastiche at times, it never does so in anything other than an entertaining way.

The game maps are uniformly well designed, and each unit type occupies a useful tactical niche. Infantry, contrary to what you might think, is actually one of the more valuable unit types, as Infantry or Mech units can take over cities, the ownership of which adds funds to your war chest. They also have the virtue of being very cheap to produce. Scout units cut through the Fog of War to act as spotters and are reasonably effective against Infantry units. Several grades of tanks may be produced, which are ostensibly used to dominate the terrain and fight enemy armour. Other units like APCs are utility vehicles, whilst Anti-Aircraft guns are devastating against air units and infantry alike. Artillery and Rockets can be used to conduct battle at range, adding yet another tactical option. The depth of strategy is genuinely impressive: like a multi-layered game of chess. You need to learn the capabilities of your own units and those of the enemy, so you can lure units into ambushes without leaving your own vulnerable to counter-attack. The AI is strong, which means you really have to use your imagination to out-flank and out-think the Black Hole COs, especially if you want to get that coveted S rating at the end of the mission. It's sometimes wiser to use diversionary tactics to tie down the enemy force, whilst you sneak an Infantry unit towards the enemy HQ aboard a Transport Helicopter or APC, rather than go toe-to-toe on open ground against a superior force.

If you've played either of the game's predecessors on GBA, all this should sound very familiar. The clue to the difference between this game and its progenitors is in the name: Dual Strike. Battles can now take place on two fronts, utilising both screens of the DS, and once the battle on the secondary front is concluded, the victorious CO joins the main front, doubling up in a Tag Team against the opposition. Swapping COs in Tag battles allows them to build up their power meter, and once both COs can use their Super Power, this allows you to perform a Dual Strike: i.e. each CO takes control of your forces for a turn within the same day, effectively doubling your striking power. If this is done at the right moment, it can decisively turn the tide of a battle. The Dual Strike adds a whole new dimension to the game, and takes some practice to implement correctly. When battles are contained to a single front, the second screen is not wasted. Though orders are confined to being given via the touch screen, the top screen will reveal information about the unit or terrain highlighted by the action cursor, which can give you the edge in making sure you don't leave one of your tanks within firing range of an enemy artillery unit, for example.

The other game modes, barring Combat, show equal depth, too. War Room is a custom battle mode that allows you to set up engagements on a variety of maps, tailored for 2 COs, 3 COs or 4 COs, with the objective being to record the highest score, almost like an arcade mode. The Versus mode is similar, except that you can play either against the DS, or link up to play another person. Survival mode tasks you to achieve victory on three maps, with limited money to buy units, or a limited number of turns, or within a certain time limit. All of these game modes can eat up a considerable amount of time, should you be inclined to let them to, and add extra longevity. The Combat mode, however, has left me somewhat nonplussed. It uses the same rules and units of the turn-based game, but transports them to a real-time environment. Personally, I don't like it, don't think it works very well and seems a little redundant, given that the turn-based game is so brilliant. A tip of the hat to the RTS crowd? Maybe. Thankfully, at least it can be ignored.

The game's visuals are basic, but the incredible gameplay makes up for it

Whilst we're on the hunt for flaws, other elements of the game aren't immune to criticism either. Graphically, Dual Strike is for all intents and purposes identical to its immediate predecessor and won't make your DS sweat too many electrons. The touch screen integration is adequate without being spectacular, and a bit more variety to the music would have been nice. You would also be well advised to ensure that you play the game with a fully topped up battery, too. There's nothing worse than spending half an hour grinding your way through a two-front battle and the screen suddenly going black, just as you remember you've not saved the game mid-mission. I speak from bitter experience here, believe me.

These are all relatively minor quibbles, though, and will be quickly forgotten in the heat of battle. There's so much else about the game to love, from the charmingly twee animations of soldiers jumping up and down on buildings as they capture them, to the Anakin Skywalker-style "NOOOOO!" screams of the COs when one of their units is wiped out on the battle animation screen. It would be a mistake to be fooled by the teen-friendly Manga styling and cheesy dialogue into thinking this isn't a full-blown serious strategy game. Two front battles are time consuming and challenging in equal measure. You really need to be able to think a few turns ahead and plan your attack properly if you want to get the highest mission ratings, as fighting reactively will only lead to defeat. This is a game you win by thinking ahead and taking the initiative, not letting the enemy come to you. As a turn-based strategy, Advance Wars: Dual Strike quite rightly rubs shoulders with the likes of Civilization IV on merit: it's one of the best strategies of the year. As a DS title, along with Meteos and Nintendogs, it's one of the standout reasons to own a DS. Go buy.