Actor Allusion: Kiefer Sutherland was cast as the new voice of Snake in part as a reference to his role in as Jack Bauer in 24. After seeing Snake in the prison camp, Chico starts to panic and begins drawing attention to them. It doesn't take long for Snake to apply a sleeper hold on him while saying "Don't fight it."
Kiefer also faces off against beings that replicate humans, much like his fatherdid (he provides the vocals for Raiden in "Jamais Vu" mission).
Billing Displacement: Kiefer Sutherland's name comes last in the cast list of the opening credits of Ground Zeroes. But he is billed first in the end credits. This also happened to David Hayter at the beginning of Peace Walker.
The Cast Showoff: Not only did Stefanie Joosten provide the likeness, voice, and motion capture for Quiet, but she also sings "Quiet's Theme" on the soundtrack.
Before The Phantom Pain's release, Midge Ure's cover of David Bowie's "The Man Who Sold the World" was not nearly as widely known as the original or the Nirvana cover.
Dueling Games: Among some fans, rivalries are already popping up with the likes of Fallout 4 forthcoming. The game is also coming out the same day as the Mad Max game.
Dummied Out: Modifying game files on the PC version shows that child soldiers were originally going to be able to be killed, with the player receiving a hefty Heroism penalty for it.
Executive Meddling: In March 2015, Konami underwent an inexplicable change in brand management policy, with all indications pointing to the higher-ups becoming frustrated with games becoming associated with the studios and certain people, especially Kojima, who actually developed the games rather than the Konami brand. As a result, they started to remove all mention of studio and director names from advertising and the front of game boxes.note Including games already released. Kojima Productions was affected the most by this change. Naturally, this clashed violently with Kojima's Auteur License, which led to a fallout. Kojima left Konami a month after the game was released and Kojima Productions was disbanded entirely and renamed into a generic "Konami" studio. Konami has stated that they will continue to develop Metal Gear games without the involvement of Kojima. As you can imagine, this utterly destroyed what goodwill fans had towards Konami.
Many fans and sources speculated that The Phantom Pain was actually a Metal Gear game well before it was announced as such, thanks to the clues left in the original trailer.
A number of fans had figured out that the creepy child with a gas mask was actually a young Psycho Mantis, or that he was at least involved with the mysterious organization of "Those Who Don't Exist". This was given further credence by Game Informer about a month before the release of Ground Zeroes.
From his reveal, there were much speculation being thrown around about Eli being a young Liquid Snake, and with very little talk on the matter, only strengthened the suspicions. So, when it turns out that he actually is Liquid, no one was surprised.
Regarding a huge plot twist revealed at the end of the game: several people guessed that "Venom Snake" was a clone of Big Boss. While this isn't entirely true, he is a separate individual. Rather than being a complete clone, he made in to a body double with Magic Plastic Surgery and hypnotherapy.
Lying Creator: Hideo Kojima kept insisting that "Project Ogre" was not, in fact, a production title for Metal Gear Solid 5 prior to the reveal of The Phantom Pain. Turns out, it was. However, this is actually an instance of him being misquoted, because his original statement was in reference of Ground Zeroes at the time. Hideo Kojima also refersMetal Gear Solid V as a spin off and not a numbered entry. Which makes sense, considering you aren't actually playing as anyone from the Big Boss bloodline.
The first Ground Zeroes trailer was shown at a Tokyo event commemorating the 25th anniversary of the series.
Likewise, the trailers for the Déjà Vu and Jamais Vu missions were shown during the 15th and 25th anniversaries of Metal Gear Solid and Snatcher, respectively.
One of Us: Stefanie Joosten, who provides the likeness and voice of Quiet, is also a gamer and a longtime fan of the Metal Gear franchise. She even has a Twitch channel and a YouTube channel where fans can watch her play the game.
The Other Darrin: David Hayter was replaced by Kiefer Sutherland as the voice actor for Snake to help "recreate the Metal Gear series." Meanwhile, Ocelot is being voiced by Troy Baker instead of Patric Zimmerman. In the latter case, Ocelot at least has precedent, as the younger version of him was voiced by Josh Keaton in Metal Gear Solid 3 and Portable Ops. This also happened with Zero, as Jim Piddock thought the offer Konami made him was too little.
Paper-Thin Disguise: Meta example. The Moby Dick Studio marketing stunt was intentionally made as transparent as possible to get people hyped for The Phantom Pain.
Talking to Himself: Kiefer Sutherland voices both Snake and Ishmael, and the two share a scene together at the start of The Phantom Pain. It has been confirmed that he voices the medic that appears in Ground Zeroes, but his voice was altered digitally. The trope becomes literal when it's revealed that Ishmael is the real Big Boss, and Snake is really the medic who, through plastic surgery and hypnotherapy, has become Boss's body double.
Metal Gear Solid V was originally announced in two unrelated incarnations. The first was Metal Gear Solid: Ground Zeroes, a tech demo for Kojima Productions' new FOX Engine. The second, The Phantom Pain, was presented as a new IP from the mysterious Joakim Mogren's Moby Dick Studio. On March 27, 2013, series creator Hideo Kojima revealed that Ground Zeroes and The Phantom Pain were the prologue and main story, respectively, of a combined Metal Gear Solid V.
Former Big Boss voice actor David Hayter messed with the fanbase by leaving a lot of comments suggesting that he'd be involved in The Phantom Pain a small capacity and denying that he was involved at all.
After dataminers found evidence that there was a third chapter meant to be included in the game, Kojima made a series of tweets that featured the number 3 (such as complaining that a television show he likes never had a third season).
Troubled Production: The game was intended to be series creator Hideo Kojima's masterpiece, but it also marked the end of an era, as it was his final project for Konami due to a contentious production.
Despite the game's auspicious reveal (with the main game being announced only by its subtitle and helmed by a "Moby Dick Studios", a fake name for Kojima Productions), the project faced controversy immediately when it came to light that long-time Solid Snake/Big Boss voice actor David Hayter was unceremoniously fired in favor of actor Kiefer Sutherland (who also provided facial capture for the Big Boss character). While it was suggested that Kojima did so in order to avoid paying a higher salary for Hayter, the latter contends that he was never approached about the issue and still harbors resentment.
In March 2015, it came to light that Konami restructured their corporate offices, with Kojima apparently out of the company as a permanent employee and his production studio intended to be disbanded at the end of Phantom Pain's production. This was followed by Kojima's name and company being removed from all marketing materials, including the final cover art for the game and future releases of Ground Zeroes and The Legacy Collection. Over the next few months, several people (including voice actress/singer Donna Burke, composer Rika Muranaka and Snake's Japanese voice actor) publicly spoke out against Konami for their poor treatment of Kojima. This also resulted in the cancellation of Silent Hills.
In April 2015, an online movement began to express questions about the likeness of a doctor featured in one of the trailers to real-life neurosurgeon Sergio Canavero, who was believed to be part of a viral marketing campaign for the game. In response, Canavero denied any involvement with the project and decided to sue Konami for unauthorized use of his likeness.
Several months later, a damning report from Japan's Nikkei news service came to light that exposed the circumstances behind the game's development. It was reported that Kojima became a pariah because Phantom Pain was delayed, leading to its production budget exceeding $80 million U.S. dollars by April 2015. It was also revealed that Konami executives (having restructured their efforts more towards mobile games and its ancillary divisions like pachinko machines and health spas) was overseeing Kojima Productions, now renamed "Number 8 Production Development", with an iron fist. Employees were reportedly monitored on social media and on emails, and publicly shamed if their lunch breaks went for too long. Additionally, it was suggested that making mistakes at Konami led some employees to be transferred to menial office tasks in other divisions until they quit the company.
In the finished product now, all the signs are there — an abrupt and Disappointing Last Level, with several promised features not coming to fruition, the game's Twist Ending revealed suddenly and out of context, and the game's True Final Boss deleted and reduced to unfinished cutscene footage as a special edition Blu-Ray extra. An entire third chapter of the game appears to have been cut when it became apparent that the game was not going to break even for Konami. It's rumored that the game has become a Creator Killer for Konami's AAA game production, though the company has publicly denied this.
Urban Legend of Zelda: Fans of the Metal Gear series all over the world are beginning to believe that Chapter 3 is just hidden, not outright cut from the game. While Dataminers have mine the PC version and found no data of Chapter 3 aside from the title "Peace", the Console Versions have not been touched in any way. The console versions are 5GB larger than the PC version, so people are speculating that Kojima has been indeed playing the players "like a damn fiddle" and cut chapter 3 from PC but left the Console intact. Whether or not this is true, the disappointed fans can now cross their fingers and hope for the best.
What Could Have Been: It has been said that the sheer amount of content cut is the true "Phantom Pain" of the game.
Several hallmarks of the other games were removed from the game in order to make the game more realistic and serious, such as Ration-based healing. Originally, Kojima thought about removing the trademark exclamation point, in favor of realistic expression from the enemy (as had been planned for MGS4 as well). Thankfully, the grandfather clause prevailed.
DLC was planned for Ground Zeroes beyond the Xbox/PlayStation exclusive content, but it was shelved so The Phantom Pain wouldn't be delayed.
For fans particularly disappointed by the game's ending and the manner of Eli and Mantis leaving,a reel detailing a "phantom episode" centered around them has surfaced from the CE bonus content. Eli would have absconded from Mother Base with the ST-84 Metal Gear, Mantis, and the child soldiers to form his "Kingdom of the Flies," and the episode would have culminated in a battle between the Diamond Dogs and Eli piloting the ST-84. After the battle, Eli would soon affirm to Snake his everlasting hatred, marking the genesis of his character as it would be known in Metal Gear Solid. The fact that so much of Eli's storyline and development seems to have been compressed into this episode suggests that this was to be an intended finale of the game. The reason why it was cut is currently unknown, but there are many different possible reasons, the most likely of which are either a), the content (after all, you are bombing a bunch of child soldiers) or b), the Konami-Kojima dispute mixed with budget problems. This case is rather unusual seeing as it was such a key portion of content. Fans initially wondered if the episode would be released as DLC, though after the announcement of an MGSV Updated Re Release, Konami's community manager confirmed that the episode will not be released.
In addition to the cut "Kingdom of the Flies" mission detailed above - and presumably the cut content to the second chapter - a title card under the name of Chapter 3 - "Peace" was found during datamining of the game's files, which indicated an entire third chapter may have been cut, though Konami has since claimed that an officially announced nuclear disarmament event (whose ending cutscene has been leaked) is the third chapter.
At one point you were supposed to be allowed to bring the Battle Gear into missions, but this was scrapped because it was too much of a Game Breaker.
Prior to release, it was stated that everyone would be able to create their own unique Mother Base. While not outright confirmed, this appears to have been scrapped due to time constraints, as everyone has the exact same Mother Base apart from color. To that end, the proposed feature allowing players to access their Mother Base using the smartphone app was also cut.
Another feature mentioned prior to release was that players importing data from Ground Zeroes could return to Camp Omega. However, it seems that this was removed.
There is a groove on the back of Sahalenthropus that suggests that it would have been combined with an AI Pod similar to Peace Walker. Handwaved in-universe by Skull Face, who adamantly refused to allow Sahalenthropus to be controlled by AI, referencing what happened to Peace Walker in the process.
Data miners have found audio files in the game indicating that Skull Face was going to be a boss battle. And following the completion of the battle the player would have been given a choice: either kill him or take him back to Mother Base as a prisoner.
Even though the helicopter that served as your support in Ground Zeroes, here referred to as an HP-48 Krokodil makes multiple appearances as an enemy helicopter and would serve as an excellent support helicopter, no option to swap to it exists, and the default UTH-66 Blackfoot helicopter is the only option available.
There's unused concept art featuring an adult Chico, who would have filled a role a lot like Null (child soldier brainwashed by sinister program), from Portable Ops.
It is believed that the song "A Phantom Pain", due to its lyrics, theme, and being an original song made for the game, was originally intended to be used in a cut version of the intro or ending.
Word of God: According to the Piggyback official strategy guide for The Phantom Pain, the enemy commander who takes control of one of Mother Base's platforms in Mission 22 ("Retake the Platform") is actually the same soldier who helped Miller to his feet during the XOF attack at the end of Ground Zeroes.
Word of Saint Paul: Quiet's voice actress, Stefanie Joosten, personally disproved the "Chico is Quiet" theory. This is confirmed in-game when it is revealed that Quiet is dressed the way she is because of her getting set on fire by Ishmael and Ahab in the prologue.