Metal Gear Solid: Peace Walker

Metal Gear Solid: Peace Walker (メタルギアソリッド ピースウォーカー) is a game in the Metal Gear series. It was released for the PlayStation Portable in 2010. It explains the story of Big Boss and leads up to the events of the founding and the creation of Outer Heaven. The game was officially announced at Sony's E3 press conference on June 2, 2009. Hideo Kojima designed, wrote, produced and directed the game. The theme song for the game is titled "Heavens Divide."

The game is set in 1974, ten years after the events of Metal Gear Solid 3: Snake Eater, four years after the events of Metal Gear Solid: Portable Ops, and just two years after the events of the Les Enfants Terribles project. The setting of the game takes place in Costa Rica.

The game was released in Japan on April 29, 2010; North America on June 8, 2010; Europe on June 17, 2010; and the UK on June 18, 2010.

On November 8, 2011, Peace Walker was re-released as a component of the international versions of the Metal Gear Solid: HD Collection for both the PlayStation 3 and Xbox 360.

Story
For a full summary of the story, see Peace Walker Incident.

The year is 1974. In Costa Rica, an unknown army of well-equipped soldiers has taken over the defenseless country. The soldiers have also brought along a nuclear warhead labeled "Peace Walker", to set off their last nuclear warhead for deterrence, and demonstrate their power with the perfect deterrent. Big Boss is asked to save the country along with his Militaires Sans Frontieres (Soldiers Without Borders). It is later learned that the soldiers that invaded the country are a rogue CIA unit, as well as the fact that the Militaires Sans Frontieres' client, a University for Peace professor named Ramón Gálvez Mena, is actually an agent of the KGB. If Big Boss fights them then he will become an enemy of America. Eventually, Big Boss and his soldiers would come to be known as the founders of Outer Heaven.

Gameplay
Some changes have been made to the standard Metal Gear formula. Movement is done with the analog stick; actions such as co-op actions use the directional pad; melee actions, which include multiple throws into a crowd of enemies, uses the R button; weapons uses the L button with the R button. The player is unable to move or shoot while laying down and while pinned to a wall. The player can set the control system according to Metal Gear Solid: Portable Ops, Metal Gear Solid 4: Guns of the Patriots, or Capcom's Monster Hunter.

The Comrade System from Portable Ops has been removed in favor of co-op gameplay, with two players in the main missions and up to four players in the boss missions called Co-Ops. Players can choose one of various different load-outs including one's camouflage.


 * Naked: Wears only light clothing. Players who use the Naked uniforms are able to move fast, at the expense of lower stealth, weaker defense, and fewer items.
 * Jungle Fatigues: A balance of stealth, defense, weapons, and inventory. Available in multiple camouflage patterns.
 * Sneaking Suit: A different version of Naked Snake's uniform from Portable Ops, the Sneaking Suit allows players to move without generating foot noises and have higher camouflage compared to other suit while moving. Players can carry up to five items and six secondary weapons.
 * Battle Dress: A heavily armored variant, players equipped with the suit can carry a third primary weapon and absorb much damage at the expense of less items, slow movement speed, and a lower camouflage index.
 * Tuxedo: Players who wear the Tuxedo can carry many items at the expense of less secondary weapons and camouflage index.

There are several actions that can take place when two Snakes are next to each other. Snake-in allows players to hold on to each other as one player leads the way. This also allows the players to fire on the move. Other co-op actions include holding up closing doors, performing CPR on falling comrades, sharing items, and acting as a spotter for other players whose vision is obscured. The game adopts certain mechanics from Metal Gear Solid 4, such as the ability to move while crouched, the over-the-shoulder view, the CQC system, and the ability to search held-up/knocked out soldiers. In addition, any items that are procured on site when such items are also maxxed out in capacity (such as various recovery items and ammunition) can still be picked up and submitted to Mother Base, in a manner similar to the item exchange from Metal Gear Solid 4 or the Deliveryman career in Portable Ops. The truck from Portable Ops, where players can bring subdued enemy soldiers for recuitment, has been discarded in favor of the Fulton Skyhook, which players attach to subdued soldiers and prisoners. In addition, the standard formula of procuring weapons on-site has been limited to throwing/placable weapons, items, ammunition, and uniforms, and recruiting soldiers, unlike in Portable Ops, does not allow the player to gain firearms from them. In addition, playing as any enemy soldiers is only allowed for when doing a Versus Op, and even then only when gaining the costume during gameplay, a significant difference from Portable Ops, where the player could play as the person they recruited.

The Wi-Fi recuitment system from Portable Ops has been modified. Instead of tapping the Circle button to obtain a strong enough signal from an access point, the player will have to knockout soldiers with CQC to accept them. The cardboard box used to hide from enemy soldiers is now available in two-man versions called Love Boxes, which have different variants. The Surround Indicator in Portable Ops can only be used when it's equpped in the item box. Players will also develop and use an early version of the Soliton Radar from Metal Gear Solid. The game features the camouflage index system from Metal Gear Solid 3. Unlike Metal Gear Solid 3, the player is unable to change camouflage uniforms during a mission as the point index will be entirely based on movement, position, and the size of the weapon equipped in the weapon box. The player can also use marking devices to call in artillery strikes or resupply drops.

Some of the game's cutscenes will require button inputs to advance the plot and can count towards the rating for completing a mission.

The crew management system from Portable Ops also returns through a feature called the Mother Base, an abandoned OTEC research platform in the Carribean that serves as MSF's headquarters. Aside from managing the combat, medical, intelligence, and technology research teams seen in Portable Ops, the player can assign personnel to the mess hall crew to feed the troops and keep up their morale. Rebellious or injured personnel can be brought to the brig and sickbay respectively. The player will also have a chance to capture military vehicles that appear in the game as minor bosses, such as armored personnel carriers, tanks, and attack helicopters. Up to 350 soldiers can be recuited; excess staff caught in a mission must be discharged and up to 50 vehicles can be captured over the course of the game.

Development
Hideo Kojima officially announced the game at Sony's E3 2009 conference, after running various countdowns for the announcement on a Konami website, stating that the team that made Metal Gear Solid 4 would return to help develop Peace Walker. Kojima wrote, produced and directed the game, stating that the game was not a spin-off, nor was it a sidestory. Kojima referred to both Peace Walker and Metal Gear Solid: Rising as Metal Gear Solid 5, while specifically calling Peace Walker "the MGS5 inside me."

A trailer for the game shown at E3 2009 also described it as the "missing link" in the Metal Gear series. The same trailer also revealed multiple Big Bosses, indicating multiplayer or co-op gameplay, which was confirmed by Famitsu in August 2009. Credits appear at the end of the trailer that show Kojima was writing, directing, and producing the game; Shuyo Murata was also a writer on the game; Yoji Shinkawa was the character designer; and Kenichiro Imaizumi was also producing the game. While developing Portable Ops, Kojima originally planned on only creating the overall guidelines and concepts for Peace Walker and then leave the rest to the next generation of developers at Kojima Productions. He was also planning on only being a producer of the game and focus on games not set in the Metal Gear series. He made the setting for the game in Costa Rica and created a story with themes about nuclear deterrence and the Cold War. When it looked like the story may be too confusing to a younger audience, he decided to become more involved in the development of the game and decided to direct it, feeling that it was still a little too early to leave the game in the hands of the developers without his help.

In an open letter to fans in August 2009, Kojima stated that Peace Walker would be a "full-featured" sequel that would "require hundreds of hours to complete." Koijma further stated that Peace Walker would include many features unique to the PSP and a new gameplay system. At the 2009 Tokyo Game Show in late September, a demo of the game was playable and was available to download for anyone who brought a PSP to the event, which IGN later made available on their site. A nine minute trailer was also shown that introduced the characters that would be featured in the game along with "Heavens Divide", the game's theme song. It was also revealed that Ashley Wood would be illustrating the game's cutscenes, similar to how he illustrated the cutscenes in Portable Ops. Also during the 2009 Tokyo Game Show, Kojima stated that President Richard Nixon's resignation during August 1974 might factor in the game's story. Kojima also stated: "Solid Snake's storyline has ended with Metal Gear Solid 4. But there's still a lot more when it comes to Naked Snake's storyline. The Cold War was a time where people, neither good nor evil, were manipulated by various factors, and they became good or evil. The same goes for Liquid Snake, and we'll get to see just what happened to him."

Kojima also stated that there would be flashbacks to events from Metal Gear Solid 3 and that the game's theme would be nuclear deterrence.

In early December, Famitsu stated that Peace Walker would be released in Japan on March 18, 2010, though on January 29, 2010, Konami declared that the release date would be delayed to April 29. On December 3, Konami announced that the game would be released in Europe on May 28, 2010. The following day, Konami announced that the game would be released in North America on May 25, 2010 and that an English demo would soon be available. On December 17, Konami released an English demo onto the European and North American PSP PlayStation Stores. This demo contained everything the Japanese demo had plus a new level which involved infiltrating an enemy facility located in a mountainous region. On March 16, 2010. Konami announced that the game would be released in North America on June 8, 2010, pushing the release date two weeks ahead. Also Konami announced it would be released on June 17, 2010 in Europe, while in the UK it would be released June 18, 2010, pushing the dates three weeks ahead.

Also, according to an FAQ on the official site, a few new details were revealed about the game. The reason that Konami had chosen the color yellow as being the main color for Peace Walker related materials was because the target audience was going to be slightly younger than before (school aged kids), so they went with the POP style. It was also stated that they based the Skull logo mark of the Militaires Sans Frontieres off of Gondwanaland (Pangaea). The limited edition PSP containing the logo in the bundle pack is also unique from the others, as the MSF logo is in a different spot in each PSP.

Kojima also revealed that, due to it lacking blood and less violence, Peace Walker was going to be rated "T", although he would have preferred it if it were rated "E" for Everyone.



On release day for North America (June 8), MetalGearSolid.com's president Shinji Hirano helped release the game "rugged Snake style" by posing on a customized Land Rover Defender.

Music
Peace Walker 's soundtrack was composed by Nobuko Toda. The Metal Gear Solid: Peace Walker Original Soundtrack was released in Japan on April 14, 2010. The game's theme song, "Heavens Divide" is performed by Donna Burke, and was released in Japan on April 7, 2010, coupled with the song "Koi no Yokushiryoku" as well as various other versions of both songs.

Bundles and limited editions
On January 20, 2010, Famitsu scans revealed that Peace Walker would be bundled with a PSP upon its release in Japan. The following day, Famitsu updated their website with more information. The bundle features a camouflage PSP, a pouch, a cleaning cloth, and a strap as well as a copy of the game which retails for ¥26,980. A Limited Edition bundle was also be released which includes everything the standard bundle has along with a PSP stand, dog tags, and a booklet, which retails for ¥36,980. Only 1,974 Limited Edition bundles are available.

Famitsu also released a limited edition bundle labelled "DX Pack" and is only available in Japan and from their website. The bundle contains the game, a 1000 piece jigsaw puzzle labelled "LOVE & PIECE", a clear poster, and a water bottle labelled "PEACE WATER." It was released on April 4, 2010 for ¥8,495.

On March 16, 2010, Sony Computer Entertainment America announced that Metal Gear Solid: Peace Walker would release an entertainment pack that includes a "spirited green" PSP 3000, the Peace Walker UMD, and a free PSN movie voucher. This entertainment pack of Peace Walker also has exclusive in-game items like a FOX camouflage uniform. A stealth gun feature that can also be unlocked early in the game. A Collector's Edition was also announced on April 12, 2010 that also included an exclusive art book.

At GameStop, the preorder bonus for pre-ordering Peace Walker was a bandana. Finally, GameStop and Konami announced that GameStop would make available an exclusive Limited Edition "Big Boss Pack" which is similar to the Japanese bundle. It features a camoflage PSP-3000, "Premium" carrying case, code for downloadable content unlockable early in the game, code a downloadable movie from the PlayStation Network, 4GB Memory Stick, and a copy of the game. According to the Kojima Report Podcast, the camoflauge PSP-3000 is a camo pattern that is called "Skull Camo" for its incorporation of the icon that identifies the Militaires Sans Frontieres (Soldiers Without Borders).

A Limited Edition of the North American version of the game was also released. Appearing in a black packaging with the Peace Walker logo on it. The Limited Edition contains the game and a miniature full color art book.

On June 30, PlayStation Network released a new downloadable wallpaper depicting Peace Walker.

Metal Gear Solid: Peace Walker HD Edition
Metal Gear Solid: Peace Walker HD Edition is a Japanese exclusive HD re-release of Peace Walker. The release of the HD Edition is likely due to the exclusion of Peace Walker in the Japanese version of Metal Gear Solid: HD Collection. It was released on November 10, 2011 for the PlayStation 3 and Xbox 360.

The PS3 version implements a new system called "Transfarring" which allows the player to switch the game between home and portable consoles, thus allowing continuous gameplay of the same file between systems. Peace Walker is transferable between the PS3 and PSP.

New features include: right analog stick compatibility, rumble support, high quality sound, and trophy/achievement support. Visually, the menus and other areas have been completely remade.

Metal Gear Solid: Peace Walker HD Edition Premium Package
Metal Gear Solid: Peace Walker HD Edition Premium Package is a limited edition of Metal Gear Solid: Peace Walker HD Edition. The Premium Package comes with a Battle Dress Snake action figure, a copy of the game, an art book, and a soundtrack. The PS3 box art for Peace Walker HD is available with either Big Boss or Kazuhira Miller on the cover. By paying extra, players will also receive a Peace Walker mug cup and a Kazuhira Miller Play Arts Kai figure.

TGS fans
During the 2011 Tokyo Game Show, uchiwa fans were planned to be issued regarding Peace Walker HD. There were four fans, each containing one of four characters in the game: Naked Snake/Big Boss, Kazuhira Miller, Huey Emmerich, and Paz Ortega Andrade.

DLC passcode/Promotional products
During the development of Peace Walker, various promotions were being made using various products. Collecting these products also results in getting a passcode that will allow special T-shirts to be unlocked in-game, as well as soldiers to be recruited that allow these shirts to be unlocked. Some of the promotional items include eight Mountain Dew collectable cans, specific AXE body spray products, Lawson book award, Piece Walker Doritos, HORI, a limited edition Walkman, Uniqlo T-shirts, and a special promotion from the manga Arakawa Under the Bridge (the last of which also has a special weapon). With the exception of HORI, the Walkman, and the Uniqlo T-shirts, most of the promotions were available in Japan only.

Mountain Dew cans
Mountain Dew, during the promotion of Peace Walker 's release, released eight specially developed Mountain Dew cans that have the Peace Walker characters on them (one for each can). The code included on the cans (which are found on a special yellow tape on the side of the can) allow the player to unlock T-shirts promoting Mountain Dew or Pepsi NEX.

AXE Body Spray products
Certain AXE HP products were developed that included a passcode that allows the player to unlock a T-shirt promoting AXE.

Lawson MGSPW book award
Passcodes given out at certain Lawson stores, known as the MGSPW Lawson book award, will not only allow players to get a T-shirt on Lawson, but also a stealth gun earlier in the game than usual (similar to the Big Boss Bundle and the Peace Walker Entertainment Pack) and an original art book.

Metal Gear Solid: Piece Walker
A Doritos-brand T-shirt can also be unlocked when doing Piece Walker in a specialized event by Frito-Lay.

HORI Original Accessory Brand
A limited edition bundle of HORI accessories was released during Peace Walker 's release. The bundle contained a camouflage pouch, three stickers that contained, individually, the title of the game, the Peace Walker logo, and the logo for Militaires Sans Frontieres, a specialized "shell" for the PSP that is colored green and has the Militaires Sans Frontieres logo on the back, a light green cleaner strap with the title and logo for the game on it, and a DLC passcode allowing for the player to unlock a HORI soldier and a T-shirt that came with him/her.

Limited Edition Peace Walker Walkman
A limited edition Walkman was released that was colored in green camouflage patterns, and also came with three minutes worth of recharge time, a pre-recorded soundtrack for Peace Walker, and a DLC passcode that allows the player to recruit a Walkman soldier as well as gain a T-shirt relating to the Walkman from him/her.

UNIQLO T-shirts
14 specially designed UNIQLO T-shirts were unlocked that contained a DLC passcode on each T-shirt. When the passcode is given, the player will recruit a UNIQLO brand soldier as well as unlock the T-shirt that the passcode came from with him/her.

Arakawa Under the Bridge
On June 17th, 2010, a joint promotion effort by Kojima Productions and the romantic comedy manga series Arakawa Under the Bridge released downloads for three T-shirts, each depicting one of the characters, a special magazine type called "comic mag" that's based on Volume 6 of the manga, and a magazine based on the July 2010 issue of S-F magazine. About seven days later, on June 24th, they released three more T-shirts from that series, and released another "comic mag" this time based on Volume 8 of the manga.

Metal Gear Solid: Peace Walker Official Art Works
On February 15th, 2011, Yoji Shinkawa unveiled plans to make an art book containing all the concept art and storyboard for the game Metal Gear Solid: Peace Walker. It was released two days later. It is currently available only in Japan and was released by the people behind the Ultimania guides for the Final Fantasy series.

Reception
Peace Walker has received very positive reviews. According to GameRankings, the game has received an average of 88.75% based on 44 reviews. Metacritic gave the game a metascore of 89 out of 100 based on 66 reviews. It was given a perfect score of 40/40 in the May 5, 2010 issue of Famitsu, making it the first PSP game (and the fourteenth game overall) to receive a perfect score from Famitsu. However, gaming blog Kotaku points out that there is a potential conflict of interest for Famitsu as former editor-in-chief Hirokazu Hamamura appears in print ads and on a Konami website actively promoting the game. PSM3 awarded Peace Walker 91% commenting on the game's ability to "take the best bits from every Metal Gear Solid game — the recuitment tricks... from Portable Ops, the camouflage and multi-player from MGS3: Snake Eater, the stripped-down controls from Metal Gear Solid 4 and the bonus missions from VR Missions." IGN gave the game a score of 9.5/10, stating that it "is probably the biggest game in the Metal Gear series, and it's only on Sony's smallest system."

Sales
Despite the critical acclaim and Konami's inital hopes that the game would be an international hit, sales of Peace Walker have been very poor outside of Japan. In Europe, the game failed to chart in most countries and placed 13th in the UK in its first week. By its third week, Peace Walker fell out of the top 40. In America, the game similarly failed to make the top 20 during its first month, selling only 52,000 physical UMD copies, a markedly worse performance than Metal Gear Acid. However, with the PSP's digital content delivery option through PSN, it has been noted that perhaps sales on the PSP should been counted differently since digital downloads for the PSP and PSPgo are not counted. Industry analyst Mike Hickey told IGN that the "PSP platform sales have faded meaningfully, and likely was a significant contributor to Peace Walker's weak sales." However, Konami has stated that they have a profit of $15 million from sales of Peace Walker and the Pro Evolution soccer games, but they did not provide sales figures for Peace Walker. They have however, said Peace Walker sales helped the Metal Gear games sell 1.2 million copies for the quarter.

Awards
Peace Walker received the Best of Show and Best PSP Game awards during the 2009 Tokyo Game Show. IGN put the game in its Best of 2010 list, garnering awards for Best PSP Game of the Year, Most Addictive Game, Best Visuals, Most Bang for Your Buck, Best Story, Best Co-Op Game and Coolest Atmosphere.

Trivia

 * Series creator Hideo Kojima makes a cameo in this game as a recruitable soldier for MSF. He can be recruited by selecting the truck in the Crater Base garage with the license plate "CENTRO AMERICA 63824 PEACE SENTINEL." In addition, because of the nature in which he is recruited, he is the only normal soldier who can be fired and then rehired by repeating the recruitment process. In fact, the plate numbers indicate Kojima's birth date: 24th August 1963 (yy/mm/dd).
 * In some cases, the series tagline "Tactical Espionage Action" has been replaced by "Tactical Espionage Operations."
 * Similar to Metal Gear Solid 3, a timeline is displayed prior to the credits, which includes entries on Huey, Big Boss, and Miller.
 * Big Boss and the soldiers he has recruited can perfom Leaps of Faith into straw boxes called "Assassin's Straw Box" in the style of Altair and Ezio, complete with the eagle cry. Jumping to the straw box prompts Miller to provide trivia about the box's history.
 * It is believed that one of the main plot points, regarding human beings not being able to execute the rules of deterrence due to human nature, was inspired by real life story of Stanislav Yevgrafovich Petrov. Petrov, after receiving a false positive of a missile attack from USA, chose not to report to HQ. In 2006, he was awarded a medal from the UN for preventing World War 3.
 * Similarly, at one point, there was a mention of a Soviet submarine commander refusing to fire on a nuclear weapon carrying American destroyer during the Cuban Missile Crisis.
 * Due to the broader target audience for this game, this is the first main Metal Gear Solid game to be rated "T" (not counting Metal Gear Solid 4: Guns of the Patriots which included a code that can tone down the game to a T rating) and the second of any Metal Gear game to be rated "T" (the first was Portable Ops Plus, an expansion pack of Metal Gear Solid: Portable Ops). Censorship standards in Japan also meant that a cutscene involving electrical torture had to be heavily edited in the Japanese release, by instead featuring the use of laughing rods, and disregarding any other story references to the torture. The scene remains uncensored in releases outside Japan.
 * The Japanese version of Peace Walker includes real-life products, such as Doritos, MTN Dew, Pepsi NEX, Bon Curry, AXE Body Spray, and various gaming magazines, namely as a joke towards the audience about product placement. In addition, if players utilize various passcodes in Japan, they can also unlock T-shirts relating to these products. These items had their names changed in the American release, presumably due to trademark laws outside of Japan. Consequently, the T-shirt bonuses as well as the briefing files relating to those items were also removed from the international versions. The only exception to this was the Sony Walkman, which is presumably due to its major role in the game.
 * Peace Walker is the first Metal Gear game to have the player go through multiple torture sessions since Metal Gear Solid/Metal Gear Solid: The Twin Snakes. In addition, similar to Metal Gear Solid 4, Peace Walker is the second game since the original Metal Gear that does not include both speakers portraits when communicating via the radio (in Peace Walker and Metal Gear Solid 4: Guns of the Patriots, Big Boss/Solid Snake's portrait is absent while his portraits of his contacts are visible during various conversations between missions/cutscenes and during Codec calls, respectively. In Metal Gear, the only person who has a portrait in the transciever mode throughout the game is Solid Snake). Although Naked Snake didn't actually have a portrait in Metal Gear Solid 3: Snake Eater, he did nonetheless appear in the background during radio conversations. It is also the first game since Metal Gear to not have the player crawl on the ground.
 * Peace Walker is the first and so far only Metal Gear game to not have a multiple playthrough option after completing the main game. On a related note, it is also the first and so far only Metal Gear Solid game that has the Tuxedo (or a similar outfit) that does not need the full completion of the game to unlock (instead, it only requires the first ending for it to be unlocked).

"HORI HORI t-shirt, identical in basic characteristics to Jungle Fatigues. HORI fans, show your support!"

- HORI description in Metal Gear Solid: Peace Walker

"T-shirt designed by Uniqlo. Identical to Jungle Fatigues in basic characteristics. Now you can look good while getting your sneak on!"

- UT (all T-shirts) descriptions in Metal Gear Solid: Peace Walker

Easter eggs

 * While searching through the trucks, the player can come across the following things: Hideo Kojima will be in one of the trucks and Snake will say "Director!" ("Mr. Kojima!" in the English version). Another one will have gears (the machine part), at which a confused Snake will say "Metal... Gear?!" and another one has a poster of Mei Ling during Metal Gear Solid(the truck's plate is her original codec frequency). The last one has numerous plushes of Solar Boy Django's sunflower-like companion, Master Otenko from the Boktai series (at which Snake will yell "SUNLIGHT!")
 * In a briefing file with Cecile, Kaz will talk about how her name (Cecile Cosima Caminades) sounds similar to Cecile Kojima Kaminandesu. In Japanese, Kaminandesu can be translated into "is God", therefore translating the phrase as "Kojima is God". She's named after a real person, Cecile Caminades, who is in charge of press relations at Konami France.
 * The player can obtain a soldier that is Hideo Kojima. His profile says "70% of my existence is made up of movies, the other 30% is up to you", a take on a famous quote from Kojima. Besides Kojima you can also obtain soldiers that has the faces of: Yumi Kikuch, Akio Otsuka, and Sugita Tomokazu who were the voice actors for Dr. Strangelove, Snake, and Kaz Miller.
 * In Extra Ops, there is a mission where the player can date Paz. During that mission, if the player has the Love Box, they can invite her into the box (actually, using a cardboard box of any sort is required for completing the mission). If the player does the mission while wearing the naked uniform, Paz will become embarrassed and will run away from them. If the player beats this mission with an "S" rank, the next time they do the mission, Paz will be in her underwear. Similarly, there is also an Extra Ops mission where Big Boss dates Kaz, and has similar methods to completing the mission as well as similar results with an "S" rank.
 * Looking at soldier's profiles contain many hidden jokes. One of the soldier says "I have a friend named Johnny, do you know him?", referring to Johnny Sasaki's grandfather. Another says "If I have a girlfriend one day, I would like to go in a cardboard box with her." Another one runs to Snake, in disbelief that another soldier believes Santa is real. Yet another reference is to a song, a soldier says "Balls to the wall, boys". Another references Forrest Gump, a soldier says "When this battle’s over, I’m gonna go home and be a shrimper. Me and my buddies are gonna pitch in an buy a big boat." See: Soldier quotes in Metal Gear Solid: Peace Walker
 * Unlocking Extra Ops 63, 64 and 65 will allow the player to play the game Pooyan. The player will have to shoot all the fultoned soldiers that appear. Pooyan is a well known Konami game. In a briefing file, Kaz tells Snake that his neighbor had a pig named Pooyan.
 * Metal Gear Mk. II made an appearance in the cutscene between Big Boss and Huey after the Pupa battle.
 * The logo for Peace Walker (peace sign with airplane) looks similar to one of the palletes in Metal Gear Solid 3 's title screen.
 * When the player shoots a soldier with the Tanegashima, a tornado will shoot up the soldier into the air and Miller will call them and say "There's a soldier hanging on the helicopter", along with other quotes.
 * After unlocking the extra mission 121, the player can go to an island where they can fight two monsters from Monster Hunter . They are the Rathalos and Tigrex.
 * Various characters from past Metal Gear games make cameo appearances as the randomly-assigned profile pictures of recruited personnel. Various fans have pointed out the following examples, though some portraits' similarities may be unintentional: Laughing Octopus; Raging Raven; Crying Wolf; Screaming Mantis; Vamp; Fatman; Fortune; Emma Emmerich; Peter Stillman; The Sorrow; The Fear; Ed; Jonathan; Johnny Sasaki; Mei Ling; Naomi Hunter; and Rosemary. Various staff members, besides Kojima, were used as well. Some faces also resemble ones used in Metal Gear Online, while others are reminiscent of characters from other Kojima projects, such as, Snatcher, Policenauts, and Idea Spy 2.5.
 * During cutscene 11 "The Man in the Crater Base", a Gekko from Metal Gear Solid 4 can be spotted on the left side of the screen during Huey's explanation. Zooming in on the bottom right corner will reveal Metal Gear REX.