"Getting back to Master Chief" is how Microsoft Studios boss Phil Spencer summed up Halo 4's agenda back at E3 2011, and if that was all there was to 343's first entirely self-produced Halo game, it would be one of this generation's costliest disappointments.
The source of Master Chief's appeal, after all, isn't who he is but where he takes us, the exotic locales his vacuum-sealed armour and scratch-proof, gravelly altruism allow us to visit. To go in search of the man beneath the suit is to forget that practically speaking, the man is the suit, a veneer of all-enabling machismo who's most of service when he's least obvious - fading into the background like a stray HUD read-out as you contemplate a valley seething with Warthogs and Wraiths, a Covenant vessel plopping out of slipspace or a ribbon of artificial land curving impossibly into the ether.
343's attempts at endowing this carefully constructed husk of a protagonist with psychological depth are predictably timid. An opening cutscene hints at the traumatic Spartan upbringing explored in Halo books and comics, but the writers are reluctant to open any real cracks in Chief's bronze fašade, shunting the brunt of the emotional wrangling to AI sidekick Cortana, whose sickly sort-of-romance with the big chap is all the more painful for an advanced case of computer senility. To say nothing of some agonisingly poignant, albeit well-realised eyebrow animations, which at one point had us scrabbling for things to throw at the TV.
Fortunately, Halo 4 isn't just about babysitting a psychotic PDA while peeling back the layers of a chunky cyborg. It's also about discovering Requiem, the Forerunner structure glimpsed at the end of Halo 3 (providing you completed it on Legendary) - an immense, hollow sphere which houses canyons of lava-veined purple crystal, dusky orange mesas, lushly knotted jungles and enormous silver obelisks, sprouting from the inner shell like stalactites. Requiem is 343's stab at reviving the mystery of Combat Evolved, the thrill of setting foot on the totally and fundamentally alien, and in that respect it's a glorious success.
It's a success, too, as a bridging point between single and multiplayer. In truth, your trip through the planet's bowels in Master Chief's impressive clogs is no more than an appetiser for Spartan Ops mode (also reviewed as a standalone deal here), which sees teams of up to four fighting their way through objective and territory capture missions as part of a side story centred on the warship UNSC Infinity, also present in the campaign. The Infinity serves as the origin point for Halo 4's competitive modes, too, now known as War Games. It's an elegant over-arching conceit which lends Halo 4 a vital cohesiveness - vital given the somewhat thrown-together feel of the initially promising plot, which quickly disintegrates into yet another race to save Mother Earth from destruction. Book-ended by, of all things, a QTE.
The utterly majestic art direction also helps with this. Halo has always done well out of the Forerunners visually, juxtaposing their sloping Aztec blues to the uniform grays of human architecture and the bulbous, sugary pinks of Covenant structures. But Requiem is a breath-taking forward leap, its bases, tunnels and high altitude platforms a beautifully shaded, crystalline whirlpool of fragmenting planes and pulsing iconography, nestled within densely accoutred forests, valleys and cloud formations.