Solid Snake may have looked like a man long overdue for retirement in Metal Gear Solid 4: Guns of the Patriots, but Hideo Kojima's favourite son has only just turned 25 years old.
The super soldier has seen plenty of action in that time, reinventing the stealth genre in the late '90s, starring in numerous spinoffs and even duking it out with Mario and Luigi in Nintendo's Super Smash Bros Brawl.
Few characters have had quite the same impact on the modern games industry as Snake, who has been pushing boundaries since his first PlayStation outing. To celebrate the battle-hardened veteran's landmark year, we take a look back at the iconic Metal Gear series.
Original Metal Gear series
Kojima introduced gamers to Solid Snake in 1987 with the release of the original Metal Gear for MSX2 computers. It was a top-down espionage affair that has little in common with the series as most gamers know it.
Snake bore more of a resemblance to an '80s action hero than a hardboiled soldier, but the core concept of going in solo and creeping around undetected were in place. The story saw the protagonist on an infiltration mission in the fortified state of Outer Heaven, where he was tasked with destroying the eponymous Metal Gear, a bi-pedal tank with nuclear capabilities.
Due to the game's success in Japan and parts of Europe, publisher Konami released a heavily-altered NES port, and followed it up with what is now considered an non-canon sequel, Snake's Revenge: Metal Gear 2. Kojima was later ask to develop a true sequel to the game, and the result was 1990's Metal Gear 2: Solid Snake.
The official follow-up was another top-down adventure, and more sophisticated one at that. The enemy AI was far superior, making infiltration a challenging feat, but Snake was equipped with an array of new tools for a deeper gameplay experience. The transceiver system was also expanded.
Solid Snake was a game ahead of its time, dealing with complex themes such as the horrors of war and nuclear proliferation. It's core mechanics would go on to serve as the blueprint for Snake's 3D debut on the Sony PlayStation, eight years later.
Metal Gear and its official sequel are difficult to track down in their original form, but players who are keen to trace the series back to its roots can find them as bonus games in Metal Gear Solid 3: Subsistence for PlayStation 2.
Metal Gear Solid series
Having saved the world from nuclear obliteration twice, Snake took some time out during the 16-bit era, before re-emerging on PlayStation with a radical new look in 1998's Metal Gear Solid.
The new Snake, an amalgamation of Jean Claude Van Damme and Christopher Walken, was tasked with thwarting an armed uprising by a genetically-enhanced, renegade special forces unit called FOXHOUND.
Despite being rendered in 3D and taking place from the third-person perspective, the essence of Kojima's 8-bit works was firmly in place. Players were required to use their radar and wits to navigate the game's areas undetected, and were harshly punished for going in all guns blazing.
Commands were carried out but while switching between various modes. Snake remained in 'infiltration mode' until detection, at which point he switched to 'alert mode' to flee from encroaching enemies. After laying low in a safe place, 'evasion mode' kicked in, making radar inaccessible. This then reverted back to 'infiltration' when a timer had run down.
Snake was armed with numerous tools and abilities to help players remain undetected. He could crawl beneath objects, perform surreptitious takedowns, user cover and distract enemies by making sounds. Infra-red goggles helped him see in the dark, and a cardboard disguise could be used to outwit guards.
Although Snake went in solo, a codec device kept him in touch with allies. This was used to flesh out the storyline and provide sound strategy and gameplay advice. Upon completing the game, the codec presented players with an array of stats and assigned them with a codename based on their performance.
Metal Gear Solid was a critical smash in its day, and is often credited with popularising the stealth genre and defining the PlayStation era. As would become a series tradition, an enhanced port titled Metal Gear Solid: Integral was released for PC, followed by a remake for Nintendo GameCube under the moniker of Metal Gear Solid: The Twin Snakes - a reference to the protagonist's brother and nemesis Liquid Snake.
Kojima would not begin work on the next entry in the series until the next hardware generation. Metal Gear Solid 2: Sons of Liberty was released for the PS2 in 2001, taking the series into more cinematic and aesthetic territory.
The game introduced a new protagonist named Raiden, a rookie agent tasked with taking down the Sons of Liberty, a terrorist organisation threatening to trigger a cataclysmic environmental disaster. However, things didn't turn out to be black and white, as the new recruit later uncovered a global conspiracy.
Solid Snake may have taken a back seat in this instalment, but was still an integral part of the game and story. He is playable during the opening chapter, and appears to be on the opposing side for a short time after, until the plot begins to twist and turn.
Aside from the obvious graphic superiority, Metal Gear Solid 2 brought in a raft of new gameplay mechanics that moved the series forward. A first-person aiming mode allowed a greater degree of accuracy with firearms, refined cover mechanics enhanced the stealth gameplay and more intelligence enemy AI amped up the challenge.
Metal Gear Solid 2 received a similar level of acclaim to its predecessor. Its artistic merit was singled out for praise, with many critics hailing it as the first example of a postmodern video game. It went multi-platform shortly afterwards with the launch of Metal Gear Solid 2: Substance, an enhanced edition for Xbox, PC and PS2.
The next core entry in the series arrived on PS2 in 2004 in the shape of Metal Gear Solid 3: Snake Eater. The game served as a prequel to the entire series, following the exploits of Naked Snake (known as Big Boss in the other games) in a 1960s Soviet jungle setting.
Metal Gear Solid 3 continued the series tradition of tactically rich stealth mechanics, but taking the action out into a hostile wilderness proved to be a game-changer. New gameplay features such as camouflage were brought in to make full use of this exciting new backdrop, and the result made the formula feel fresh. Other debuting features included the 'close quarters' combat system, a stamina gauge and realistic injuries.
An enhanced international version called Metal Gear Solid 3: Subsistence was released for multiple formats in Japan in 2005, making it overseas the following year. The special edition included updated versions of the 8-bit originals, user-controlled camera operation and competitive online multiplayer modes.
Ten years after he took the PlayStation by storm, and 20 years on from his 8-bit debut, Solid Snake's swansong came in 2008's Metal Gear Solid 4: Guns of the Patriots for PlayStation 3. It was an apt end to an epic saga, following the efforts of a rapidly-aging Snake on his final mission.
Metal Gear Solid 4 harnessed the raw power of the PS3 to update the series for the current hardware generation, but its stealth roots were once again embraced. Like every sequel Kojima and co ever released, the title brought in new tools and mechanics to enrich the experience.
The inclusion of the Psyche Meter - a stress gauge influenced by environmental factors - and new equipment such as a camouflaging OctoCamo suit felt like just enough to give the game an identity of its own, while maintaining the essential ingredients of the Metal Gear series to help Snake go out with a 500-megaton bang.
Handheld titles and other releases
Solid Snake made his handheld debut in 2000 in the Game Boy Colour title Metal Gear: Ghost Babel. The game was a non-canon sequel to the original Metal Gear, borrowing its top-down viewpoint and gameplay mechanics.
Ghost Babel was developed without any input from Kojima, yet turned out surprisingly well. It brought in elements from the 3D iterations, and even added a two-player battle mode. This is certainly a contender for re-release through the Nintendo 3DS storefront.
The franchise first appeared on Sony's PlayStation Portable in the shape of the trading card-based strategy Metal Gear Acid. It was a bizarre change of pace for the series, but one that was well-received enough to warrant a sequel the following year and subsequent mobile iterations.
Metal Gear would fulfil its potential on handhelds in 2006 with the release of the excellent Metal Gear Solid: Portable Ops for PSP. Kojima acted as producer on the game, which expanded on Naked Snake's Cold War-era story.
Offering a perfect recreation of its console counterparts in the palm of your hand, Portable Ops even ventured into uncharted territory, throwing squad-based mechanics into the mix with the traditional stealth ingredients.
There was even better to come in the sector. Kojima returned to the director's chair for 2010's sublime PSP effort Metal Gear Solid: Peace Walker, another canonical title based around the adventures of Naked Snake. The squad-based tactics from Portable Ops were dropped in favour of fully-fledged co-op gameplay, marking another first for the series.
In additional to the core PSP entries in the series, Metal Gear has spawned several spinoffs in the smartphone sector. Metal Gear Solid Mobile for N-Gage was one of the best games for the ill-fated Nokia device, while Metal Gear Solid Touch was a bog-standard shooter for iOS.
In recent years, Metal Gear Solid 3: Snake Eater has added an additional dimension and found its way to the Nintendo 3DS, and Metal Gear Solid 2, 3 and Peace Walker were bundled together for the highly-recommended Metal Gear Solid HD Collection on PS3, Xbox 360 and PS Vita.
So what does the future hold for Metal Gear? Well, after setting the standard in the stealth genre for several generations, the series is shifting its focus to action-based mechanics with the upcoming Metal Gear Rising: Revengeance, a fresh start focusing on Raiden.
We're unlikely to have seen the last of Solid Snake too, given his recent cameos in such games as New International Track & Field and the Ape Escape series. You just can't keep a good gaming icon down.
Gallery - Metal Gear's 25-year history in pictures: