There's one small feature - inconsequential, really - that we noticed during our playtest of the next Metal Gear Solid that really sums the game up. Maybe even the whole series. At certain moments during cut-scenes, when a familiar character appears or there's a reference to some past event, a button prompt appears in the corner of the screen. But it's not an invitation to skip (although you can - and for the first time, you can skip codec conversations, too). It's not some kind of simon-says scripted action moment, or 'cineractive', in the uniquely horrible term coined for them this year. No: it's a flashback button.
Hitting it at an opportune moment switches playback to a cut-scene from some previous Metal Gear, filling you in on relevant details of the cast list and back-story of Hideo Kojima's extravagant spy soap opera. The series' plotline is now so tortuously convoluted and multi-layered - especially after bouts of period nostalgia that were Snake Eater and Portable Ops - that even diehard fans will need their memories jogging.
The other reason Guns of the Patriots needs a flashback button is that it's clearly throwing the kitchen sink in. Kojima has been threatening to end the series, or quit it, or both, with every instalment since the first. This time is no different, and really it's no more likely to be true. But it feels true. Not just because Snake is now a white-haired warrior staring death in the face, but because the game's comprehensive roll-call makes it feel like a greatest hits. Even in the brief demo level we played, we came up against a couple of very old friends: support geek Dr Hal "Otacon" Emmerich, and erstwhile love interest Meryl Silverburgh, returning for the first time since the first MGS on PlayStation.
Otacon appeared at the very start of the demo, communicating with Snake via the screen of his invention, the Metal Gear Mk. II, Snake's robot helper and comic foil. This radio-controlled roller-skating camcorder was by far the most striking and exciting new gadget in the demo, with huge potential to ease Snake's progress. It can be taken control of at any time - Snake grabbing a Sixaxis to do so - and scout ahead, invisible to enemies thanks to its active camouflage. It can even stun guards with a whip-like electrified arm. It made early sections of the demo - set in the ruined, nameless Middle Eastern city familiar from trailers - a breeze.
Another new feature to help you as you pick your way through the maps is the 'threat ring'. Not unlike the sound indicator in the PSP's Portable Ops, this is a faint white ring that surrounds Snake and distorts and quivers in the direction of enemies making noise. It's a really elegant and beautifully realised graphical device that goes some way towards giving you a real sense of spatial awareness without the need for a top-flight surround sound system.
As you'd expect, Guns of the Patriots tinkers and tampers with the Metal Gear Solid template in other ways too. The Octocamo active camouflage system didn't feature in our demo, and nor did the weapon customisation. The new stress meter - replacing the stamina meter from Snake Eater - was present and correct, and succeeded in stressing us out as we watched it creep up with every noisy blunder and awkward scuffle with the guards, although its precise impact on gameplay wasn't quite clear. The Close Quarters Combat unarmed fighting system returns in modified form, and felt more smooth and powerful than before.
By and large, in terms of features and controls at least, Guns of the Patriots feels more like traditional MGS than Snake Eater or Portable Ops did. Uninterrupted by the heavy menu usage and elaborate gameplay systems of both those games, it's a tense, exacting, crisp and relatively fast-paced stealth thriller, with a stop-start rhythm that harks all the way back to 1998. Its departures from what we expect of Metal Gear don't come in the form of some arcane new mechanic; they're more subtle, more general, but perhaps more fundamental.
The series' traditional bird's-eye view of the action has been replaced with a more contemporary free-look third-person camera. This actually first appeared in the Subsistence version of MGS3, but this is the first time a Metal Gear game has been designed around it, and it shows. The environments are more open but also more complex, detailed and multi-layered.
The demo consists of a honeycomb maze of shattered, bombed-out building shells, and our route through takes us sneaking all around its outskirts, looping and circling and doubling back, before finally heading out into the street for a confrontation with an enemy tank. Blowing this up with a rocket launcher earns the trust of the rebel soldiers fighting the mercenary bad guys, and the demo ends with a quite un-MGS running battle, accompanied by the rebels, mopping up the last of the PMC (private military corporation) soldiers. Then a cut-scene introduces Meryl and her new Foxhound unit, one of whom appears to be Frank Spencer in a balaclava.
The "no place to hide" strapline is a bit disingenuous - in this demo at least, there were places to hide absolutely everywhere. But the feeling of cover was much more fragile, and the option of shooting your way out much more realistic. Guns of the Patriots bring action to the fore more than any Metal Gear Solid to date has dared to. Snake is tooled to the nines with heavy hardware, and allowed to use it without necessarily having to run for cover in a querulous flap afterwards.
That will come as a relief to many players, but we're not 100 percent sure it's a good thing, yet. The fact is that the nine-year-old template for this game was not conceived as a full-bore shooter, and the controls and camera can't really cope with the action. Aiming is maddeningly imprecise, lock-on has a mind of its own, and the camera moves with a vague inertia which works nicely for taking in the view, but not for flicking around a battlefield quickly. It's messy, frankly, and the game feels much better when playing with the painstaking, inch-at-a-time precision you had to in previous instalments.
One thing you needn't worry about: Guns of the Patriots looks stunning. There are far more expansive, varied and showy game environments out there, it's true - the setting is almost drab in its realism - but the characters and their costumes are rendered and animated with an exquisite eye for detail, understated style and perfect, disbelief-suspending finish. Old Snake has the smouldering, craggy dignity of a Connery or Redford, and he's not even real. Metal Gear Solid has always been one of the sexiest game series, and Guns of the Patriots is just dripping with spy-fetish cool.
But it's a game with a flashback button, and all that implies. It's burdened - or blessed, depending on your point of view - with a long and complex history and a decade-old style of stealth play, and as much as it seeks to break out of that, it probably won't. It's probably going to remain a Marmite game, delighting, enraging and confusing people in equal measure. But there's no doubt that it will be a dream come true to MGS fans, and based on our demo, it's quite likely to be their favourite since the first.