When is an expansion not an expansion? When it decides it wants to be something more, something so crammed with features and new ideas that it's almost an entirely new game, albeit one still constrained by the game it has separated itself from, and while Warhammer 40,000: Dawn of War - Dark Crusade is a nice, brave attempt to elevate the Dawn of War series to heights it has never before scaled, it does come across as a venture that seems to have bitten off a little more than it can chew.

Kronus is the stage that has been set for the five existing armies to do bloody battle; each side wants control of the desert planet and none will relinquish until one triumphs, but added to these heavyweights are the introduction of two brand new armies - the Tau, a race of technologically superior aliens who also use primitive creatures to fill their ranks and the Necron, ancient robotic aliens that are hell bent on annihilating all life in the universe.

Central among the new additions is a brand new campaign mode. Scrapping the linear story-driven missions of old, a campaign map is where you carry out most of your fighting, taking it in turns invading and defending territories as you wrestle control of the planet. Acquisition points need to be gathered in order to strengthen your presence and when two armies do collide, the game switches to the familiar 3D real time battlegrounds of Dawn of War, where the tactics of taking and holding strategic points all come into play.

Despite some variety in the abilities awarded to you for attacking certain territories, such as a spaceport allowing you to travel anywhere on the map, this is a decidedly simplistic campaign map that manages the basics but not a whole lot more. Beyond attacking or defending, you just don't have much to do here; you can strengthen armies with requisition points and hire more squads as bodyguards for your commander, but beyond this it's a repetitive mix of move, attack, end turn and repeat. What the campaign map essentially boils down to is a series of skirmish maps joined loosely together by some sparse narrative and some mildly engaging micro-management. Dark Crusade hasn't the depth of the Total War games and the lack of any real variety or things to do is a disappointment. The battles do save it somewhat, even though the AI is considerably more aggressive this time around, building a base so fast that it launches an attack long before you've claimed your first strategic point, and its uncanny ability to slip from under you and build a secondary base, thus preventing you from securing a victory, does become a little troublesome. But these aren't nearly as problematic as the Strongholds, the capitals that house each of the seven armies' largest bases.

Unlike in normal battles, where you and the enemy have to build your own bases, in Strongholds they are already built, almost all of the resources are under computer control all of the advanced units are in place. You get attacked almost immediately, and the assaults don't let up until you've fought your way long and hard through the hordes that block your path. Objectives occasionally pop up from time to time, but attempting to complete these while fighting off the never-ending tide of enemy soldiers is an impossible task.

There are rewards though - the one thing that makes the campaign mode worth sticking with. Throughout your tour you gain Wargear, various armour and weapons that can be attached to your commander and vastly improve the amount of damage that can be taken and dished out. It's a neat system, turning your heroes into something a lot more functional on the battleground, rather than the guy you leave behind because he's too vulnerable. Despite a lacklustre effort, the campaign mode does have its moments; although there's little story here, each race does have some slight narrative guiding them though some of the tougher bits of the game, each has a reason why they are on Kronus and through the constant fighting you discover what these reasons are, plus there are occasions where some territories give you more varied objectives to complete, adding some variety where it's needed.

But even without the single player component, Dark Crusade impresses where it counts, with the introduction of two brand new armies. The Tau, as well as being a race so popular that it was modded into the game soon after the release of Dawn of War, are perhaps the most diverse faction to grace the game - they are an odd mix of highly technologically evolved super soldiers wearing hulking armoured suits and carrying weapons that range from laser rifles to giant shoulder-mounted cannons, and slightly more primitive lightly armoured creatures who use smaller weapons and huge beasts as their damage dealers. This is a strange but rewarding combination, allowing for some slightly more creative thinking when fighting the other six armies, mixing up your battlesuit-wearing Tau firewarriors and their laser cannons with a squad of Kroot carnivores, who jump from enemy to enemy, devouring the corpses of their fallen victims. Leading them is the Tau commander, who alone with his jump pack and arm-mounted machine gun can dish out more than enough punishment to his enemies. Together with their hover tanks and huge beasts, this is a race destined to become a firm favourite amongst Dawn of War regulars.

However, for the sheer visceral thrill of pulping your enemy into tiny pieces, none come close to matching the Necron, a race of vicious robotic aliens who are hell bent on killing everything and won't stop until all life everywhere has been extinguished. Not only are their weapons some of the most devastating yet seen, they're also damned hard to kill, often self-resurrecting after death. They have no vehicles, but also only have to worry about energy and their population cap, as they don't need the resources gathered by strategic points. Not only this, but their headquarters doesn't just build every single unit; with upgrades it can be turned into a giant, laser-wielding, flying monolith, which can teleport itself across the map and use its main weapon to leave small mushroom clouds as it destroys its enemies with ease. Best of the bunch is the Necron commander, a creature that not only has the useful ability to resurrect his dead squads by plunging his staff in the ground and forcing his dead servants to crawl back to life, but he can also eventually be upgraded to temporarily turn himself into the Nightbringer, a huge, scythe-wielding daemon that flails through enemy squads like a knife through butter. They're absurdly overpowered, constrained only by slow movement and a heavy reliance on energy to construct their armies. The other armies haven't been forgotten though; they each get a brand new unit, although these do pale in comparison to what you get with the two new factions.

It's perhaps Relic's ability to reproduce each of the varying races of the Warhammer universe that has made Dawn of War such a favourite among strategy gamers - they haven't cut corners and have made no attempt to lessen the impact of the stronger races to align themselves with some of the weaker ones. Each army has unique strengths and abilities, and with the Tau and Necron alone providing more variety in this one expansion than in most full games, this is an expansion worthy of attention. And it's standalone, so you won't need either Dawn of War or Winter Assault to play it and, yes, you can play as all seven armies in the single player, although you will need the previous game if you want to use them all in the multiplayer.

As for negative things to say, beyond the disappointing campaign mode, the game is starting to look a little old now, although it's not really that fair to criticise the looks of a game that still manages to squeeze out such detail, like the flecks of paint on the armour of Tau warriors or the huge numbers of soldiers colliding in a massive bloodbath - despite being two years old, it's a game that has aged remarkably well. It's perhaps also worth noting the audio detail put into every race, each of which not only uses a different art style but has their own distinct set of voices and sounds for each unit, helping to make each race seem individual, rather than just the same army wearing different clothes.

It's this kind of care and attention to detail that Relic have to be applauded for; they don't just roll out dull expansion packs to milk you of your cash, but instead they want to expand upon a game they obviously feel deserves as much attention as the full game, and although the new campaign mode doesn't quite work as well as it could have done, at least it's different. Warhammer 40,000: Dawn of War - Dark Crusade isn't just another collection of random missions and some new units; it's an expansion so crammed with new stuff that it's almost an entirely a new game -and not something that Dawn of War fans will want to be without.

Reviewed by Kieron Giacopazzi for AceGamez (All Rights Reserved).