Halo Wars

Microsoft's getting pretty good at not announcing Halo games. Not only did it not announce a new Bungie one at E3, but within the very same conference it managed to overlook Halo Wars completely. Given that Ensemble Studios' ambitious spin-off strategy game for Xbox 360 was announced in 2006, that raises serious questions about how long we'll have to wait to play it.

Ensemble was dodging those at E3, but despite the conference no-show it was actually demonstrating Halo Wars in a room upstairs, and even letting people like us sit down and play it, giving us our first chance to see how Microsoft's professed intent to "explore, not exploit" the Halo universe is unfolding in practical terms.

Expanding the Halo fiction isn't much of a problem for Ensemble - Bungie has a Halo bible that deals with years and years of events outside the scope of the three-game FPS arc - and Halo Wars drills 20 years into the back-story. But how the fiction actually expands is another question. The game follows the UNSC's discovery of a Forerunner artefact and their clashes with the Covenant over it, but apart from the scenario and timeline we're still in the dark. We're also not sure whether there'll be a Covenant campaign: Ensemble hasn't publicly ruled it out, only confirming that you will be able to play as the Covenant in one-off skirmish games away from the campaign. And now there are rumours of the Flood.

Whatever binds things together, though, those events will be fast-paced, brutal and very much in love with the things that made Halo so popular. Taking control of a UNSC force with a small base in the corner of a very Halo-esque environment, we're able to quickly pump out Marines, Flamethrower units (new to the series), Warthogs and of course Spartans - the Master Chief's contemporaries, who are out in force 20 years in the past - and assault a Covenant base on the other side of the map.

If it's a unit in Halo 1-3, it's probably in Halo Wars, and it probably looks very cute.

To get this to work fluidly, Ensemble had to do what nobody else working in the fledgling console RTS market has done and come up with a flexible, comfortable and intuitive control system. The team's answer is in multiple parts, but none is hard to grasp: you move a cursor across the map using the left stick, hover over a unit and press the A button to select it. Double-tapping A selects all the units of that type in your army, and holding down A allows you to drag a circular "paintbrush" selector around the map, which adds any units it touches to your selected group. Taking the fight to your enemies is equally simple: select some of your units, hover over an enemy and press X for your basic attack and Y for a special ability.

The base-building side of the game is also designed to be quick and easy to get into. It has to be: the base is the heart of your army, and if you lose all your bases it's Game Over. Starting with a grid of metal panels laid down by your orbital support vessel the Spirit of Fire (a colleague of the Pillar of Autumn, apparently - they met at the Christmas party), you select a panel and click on it to bring up a circular menu that has up to eight building options on it, allowing you to lay down a Barracks.

That circle-menu-with-eight-options concept is used throughout the game and the hard limit of eight items is by design, Ensemble's chirpy guardians tell us as they hop between E3 pods helping us to build bases and finish the fight [surely "start the fight" - Ed]. With the Barracks built, an eight-option circle menu allows for the creation of infantry and a few vehicles.

In this way your base is built up, and as you gather resources you can build more. Ensemble keeps it simple here, too, with a single "supplies" resource that you gather by building supply pads at the base (to which the Spirit of Fire pumps down more resource), collecting supplies as you stumble upon them in the world, and keeping an eye out for special Forerunner supply stations - the Wild Bean Cafes of the Halo universe.

As you gather resource, you can build reactors around the base, which gradually trigger access to more exciting equipment further along the tech tree - and Ensemble promises that a "guns versus butter" balance between combat and the economy will be spread throughout the game. Combat is a focus, but you'll always be dependent on building supplies. Lose a reactor, for example, and you can get bounced a few branches down on the tech tree, which will require investment to recover from.

You begin to get the sense, listening to and applying all this, that Ensemble's answer to the problem of making complex real-time-strategy work on an Xbox 360 pad is to reject the premise. Simple rules and a simple interface do not rule out complex strategy, their game argues. There's the rock-paper-scissors relationship between units, the question of whether to attack or to consolidate bases, the different personalities you can choose to control and their unique strengths (Captain Cutter, for instance, can deploy Elephant tanks, which are like mobile barracks that can park next to the enemy base and churn out Marines).

Expect your environment and surrounding terrain to play a key part in battles.

And with so much depth to the units already active in the Halo universe, there's the double benefit of having fully-realised armies to build into the game and allowing players to act out their God-perspective Halo fantasies. Spartans, being super-soldiers, can inevitably buff any units they commandeer on the ground, but they can also highjack enemy units like Banshees. Watching them do this en masse, each with his own cute little animation, and then turn the weapons on their previous owners together is the sort of thing Halo's fans want from spin-offs.

Obviously generating new, compelling gameplay from Halo assets is part of what Microsoft means when it says it plans to "explore, not exploit" the 360's biggest breadwinner, and stupidly indulgent fan service is an equally obvious corollary. What's more, that stuff ought to be a given for a developer of Ensemble Studios' pedigree, and the E3 hands-on suggests it is. Halo Wars' biggest challenge, though, is being the first excellent console RTS game - and Ensemble's decision to let emergent strategy do the hard work on top of simple foundations points in that direction.