Old, weary and determined to lay his ghosts to rest, it quickly becomes clear that Snake is emblematic of a narrative which is carrying too much weight on its shoulders. Full of ideas and motifs which can't reconcile their facile delivery with the more serious points underlying the game's themes, Metal Gear Solid 4 struggles to handle many of the dangling threads with a clear, focused momentum. At its outset, the original Metal Gear Solid possessed a gritty (if absurd) atmosphere, before progressing into outlandish science-fiction fantasy and all-out pop-culture psychedelia with Sons of Liberty and Snake Eater. Metal Gear Solid 4 combines these varying tones into a muddled narrative that only works for fans who can attach nostalgia and importance to the returning characters, and the variety of plot strands which eventually tie everything up. As fan-service it mostly succeeds, but on its own two feet you get the sense of a game struggling for air. Fortunately, several new characters that are introduced turn out to be genuinely likeable, and further life is breathed into existing ones by expanding on what makes each of them different.

Although it’s an extremely polished big-budget title, Metal Gear Solid 4 can be impenetrably non-mainstream. If you want more from the narrative beyond an overarching sense of drama, you have to be willing to overlook the fact that even by the series' logic, several characters implausibly alter their motives at the drop of a hat. It's a game entangled in making sense of the past, be that the story or the continued evolution of the mechanics seen in Snake Eater and Subsistence. While the control scheme is still as overly elaborate as ever in the amount of actions available, it has in most cases been modernised to allow for greater accessibility. Equally, the codec (a primary method of delivering characterisation in previous games), has been reworked and cut back. Instead of informing the player how to press the triangle button to open a locker or climb a tree five times over, Metal Gear Solid 4 refuses to hand-hold in the same way its predecessors insisted upon.

Such revision makes the experience less patronising, but previously optional information is now presented in lengthy briefings before each chapter - underlying how, in shifting weight from one traditional component of Metal Gear, Hideo Kojima has simply moved it to another. The game partially offsets this by offering expanded interaction during the cinematics, with it coming into particular effect two-thirds of the way in, as the set-pieces ratchet up arguably at the cost of the earlier and more explorative gameplay. It's here where Metal Gear Solid 4 transforms into the definitive example of the series' fusion of media - offering heavy-handed (yet beautifully choreographed) cutscenes and lavish set-pieces as it frantically tries to wrap up every loose end. Apart from a nostalgic and satisfying stealth section, these become the sole preserve of the game as one chase scene and boss battle leads into the next.

It's the bewildering visual imagination and unpredictability which sustain interest and where Metal Gear Solid 4 will likely either endear or turn off sections of its fan base. Tonally inconsistent compared to the previous three titles, it crafts a fresher experience at the cost of defining a stronger standalone identity, serving five diverse acts that depart with the series' traditional pacing to provide a wide-ranging ‘greatest hits’ of the series’ gameplay. There’s a frantic detail-laden opening akin to Sons of Liberty’s tanker chapter, the pseudo-non-linearity of Snake Eater’s middle period and even a return to the tense, anxious stealth segments which best characterised Metal Gear Solid.

Exemplifying this variety, the game's score meshes together a mix of melancholic love ballads, airy jazz, electric guitar and frenzied techno to form a hugely eclectic soundtrack. The environmental and incidental effects, voice work and expert implementation of 5.1 Dolby surround sound finish off a supremely confident package. Matching the audio, Hideo Kojima's team have always had a knack for knowing where to effectively adapt their art design to the technology they work on, and Metal Gear Solid 4 is no different. From the camera tricks, the cleverly handled colour palette and character lighting, to the impressive atmospheric effects, it’s clearly apparent how painstaking each area of the presentation is. There may be titles with better in-game animation and higher resolution textures, but the handling of Metal Gear Solid 4’s vision is overwhelmingly consistent.

Similarly, the replay value offers plenty of depth, providing a 20 hour experience filled with secrets, small touches and different styles of play. The game also features an entirely separate online component – a 16-player multi-player section featuring several modes in which people can gradually level-up, buy new weapons and make use of skills which aren’t explored in single-player. One example being nano-machine hacking that allows players to keep track of what others are doing on the battlefield.

Given the competitive nature of this multi-player, Metal Gear Solid 4 offers much-needed choice in control customisation, such as the ability to aim whilst moving forward in first-person. Coupled to a refinement of the camera system seen in Subsistence, these improvements enhance the combat and blend the stealth and action more convincingly. You no longer feel as though you're breaking the game when having to defend yourself. Similar intelligent compromises permeate the reworking of Snake Eater's camouflage system, and the simplification of its menus. In particular the psyche and stress meters enhance tension and, without being overly imposing, act as counterparts to the old stamina system.

Complimenting these numerous additions is the introduction of a portable weapons shop (not too dissimilar to Resident Evil 4’s) where players can continually purchase upgrades, sell and unlock any gear that they find. It’s a subtle nod to one of the game’s main themes: the war economy. Reducing Snake’s battlefield to a pawn shop he can make money from, it encourages a more violent approach should the player want to expand their arsenal. It’s a shame this early promise doesn’t lead to the game intelligently exploring more themes throughout its gameplay. Up to release, Metal Gear Solid 4 indicated the player would be allowed to side with various PMCs and rebel factions on the combat zone, but in reality this proves to be little more than a simplified mechanic that's a side-thought to the main action. Considering one of the dangers that Metal Gear Solid 4 preaches is of the privatisation of war, it’s a disappointment this mechanic wasn’t further explored by allowing the player the choice to sell their services to the highest bidder.

Instead, many of these ideas are explored narratively – the game being punctuated with a variety of gripping moments that, from the end of its second act onwards, continually seek to one-up each other. Whereas Snake Eater and, to a lesser extent, Sons of Liberty loaded most of their big moments for the climatic final hours, Metal Gear Solid 4 benefits from having a greater number of them throughout its entirety. As such, they help to stabilise the game’s fragmented structure by providing regular climaxes to each episode. In an effort to blur the line between cinematics and in-game action, these moments demonstrate jaw-dropping transitions from cutscene to game - even going so far as to offer split-screen segments which have multiple set-pieces on the screen at any one time. It’s a shame that although this combination comes into supreme effect in its latter stages, the game's epilogue remains resolutely passive.

But for all its indulgence, Metal Gear Solid 4 does genuinely throw moment after moment of brilliance at you. In bringing its legacy to a close, the game reveals itself to be a distillation of everything that makes the series what it is. Bold, ambitious and unlike anything else this generation, there lies an experience beyond several oddly disparate parts. A swansong to a breed of cinematic narrative which has finally reached its apex.