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.