To accomplish it the duo, well, they basically play Halo. Bungie isn't even attempting to rewrite the rulebook, but it is embellishing its regular formula with a few extra details: sloshing a bit more icing on its admittedly delicious brand of cake, if you will.
The effects and the cutscenes have taken the most significant boost. With the series running in full HD for the first time, the opening cinematic to the level is absolutely stunning, with a thundering force of UNSC vehicles streaming across a desert to take on a equally titanic Covenant armada. It's the first time in the series that Bungie has really managed to suitably convey the extent of this planetary war on the screen, and it'll leave plenty of people wishing that the Halo movie hadn't fallen through.
Once it's all finished kicking off (and it definitely does), you scroll down Halo's staple diet of wide, outdoor expanses and take on packs of enemy units. Reach isn't nearly as lush as Halo planets, and the leafless trees, bushes and shrubs lie on cracked, blistering ground - grass, when you get to it, is mottled and dank as opposed to luscious and bouncy.
Reach's aesthetic makes it the perfect home for damp, dark nooks and crannies, and Bungie is quick to capitalise on this natural extension of the planet: walkways twist and turn on top of one another, creating a multi-layered battleground that has a habit of winding around itself. The subtle skill of the level designers shows up here, the architecture always pointing you in the right direction despite it being precariously easy to get yourself lost and disorientated.
The vehicle sequence - and, let's face it, there has to be a vehicle sequence - pops you in a Rocket Hog which is, well, a Warthog with a rocket launcher. You drive around and things - Covenant, scenery, yourself if you stray too close - explode in big plumes of elaborate destruction.
And, yes, after some driving around you find yourself at the AA camps and dutifully dispatch them - letting the UNSC bombers show up in the sky overhead. They literally engulf the sky, and reign down constant streams of fire on a faraway location. That, just so it happens, is where you're off to next - though this is where the demo concluded.
It's not going to win over the detractors, but this chunk of Tip of the Spear looks like some of Bungie's best level work to date. Provided it doesn't pad out the middle sections with fluff (that means no Library, Bungie) then Reach stands a good chance of being the strongest Halo campaign yet. Judging by how many explosions featured in this demo, I think it's safe to say the team at Bungie is going to make sure it goes out with a bang.