* {{Blooper}}: [[spoiler:In the path to the GoldenEnding where Junpei realises the final "9" door is actually a "''q''", the game flashes back to the beginning when Zero relayed the rules and objective of the game. Due to a bit of {{Woolseyism}} required, the localisation changed that scene from Zero relaying the instructions verbally since "kyuu" is identical to how one would pronouce "q" to Zero slipping everyone a note with a handwritten font which obscured the "9 is q" twist since you can easily mistake the two when written down. When Junpei realises this however, the DS version forgot to change the flashback at the end where it shows the loudspeaker like the Japanese version instead of the note. The "Nonary Games" rerelease corrected this.]]
* CreatorsFavorite: [[https://web.archive.org/web/20110303123309/https://www.siliconera.com/2010/12/24/chunsoft-blog-nine-hours-nine-persons-nine-doors-the-untold-story/ According to an interview]] producer Jiro Ishii's favourite character is [[TheHeart June]]. For director Uchikoshi it's [[BigBad Zero]].[[labelnote:Spoiler]]Funny enough, both characters are actually one and the same.[[/labelnote]]
* {{Defictionalization}}: The numbered bracelets that the characters have were available as a pre-order bonus, and they acted as digital watches.
* DummiedOut: Junpei never gets the map for the bottom deck, despite eventually reaching out in every ending. Graphics for the bottom deck map exist however, along with top views of the steam engine room, confinement room, and incinerator.
* {{Feelies}}: If you pre-ordered from Gamestop online, you got a replica of the bracelets. Thankfully, it functions as a normal watch. Also, you used to be able to buy them for 5 bucks from the [[http://www.aksysgames.com/store/#999watch official store]]. Now they're collector's items that sell upwards of 200 dollars.
* GodNeverSaidThat: Even before ''VisualNovel/VirtuesLastReward'' explains it, Uchikoshi never said the hitchhiking woman in the middle of the desert was Alice and reasoned that none of the characters knew what she looked like to begin with.
* PreOrderBonus: If you pre-ordered from Gamestop online you got a replica of the bracelets. Thankfully it functions as a normal watch. Also, you used to be able to buy them for 5 bucks from the [[http://www.aksysgames.com/store/#999watch official store]]. Now they're collector's items that sell upwards of 200 dollars.
* ProductionForeshadowing: The [[spoiler:books in the Library puzzle on the true route]] discuss topics that would later appear as prominent motifs in ''VisualNovel/VirtuesLastReward'' including [[spoiler: mind-swapping, time travel, the MoonRabbit legend as well as resurrection.]]
* RoleReprise: Since this was the final ''Zero Escape'' game to be voiced, characters from this game who appear in later games in the series retain their voice actors from those games; Creator/WendeeLee and Creator/YukariTamura return as Clover from ''VisualNovel/VirtuesLastReward'', Evan Smith and Creator/TatsuhisaSuzuki (Junpei) and Rena Strober (Akane) return from ''VisualNovel/ZeroTimeDilemma'', and Creator/MiyukiSawashiro returns as Akane from both games.
* SelfPlagiarism: [[spoiler:The recreation of an event that occurred in the past as a means to facilitate TimeTravel in order to SetRightWhatOnceWentWrong by saving someone who died in the first event]] and, in particular, [[spoiler:ThePowerOfLove contributing at least in part to that TimeTravel]] is a ''very'' specific plot idea, and it's shared with ''VisualNovel/Ever17'', one of the writer's earlier works.
* UnspecifiedRoleCredit: Among the nine players in this game, Snake is the only one whose English voice actor in ''The Nonary Games'' is uncredited, being credited only as "[[CreditsGag Morphogenetic Field Voice]]".
* WhatCouldHaveBeen: Various stages of the process the game's scenario went through can be seen [[http://www.siliconera.com/2010/12/24/chunsoft-blog-nine-hours-nine-persons-nine-doors-the-untold-story/ here]].
* WordOfGod:
** According to the creator, the nine characters were based on the nine character archetypes of UsefulNotes/TheEnneagram of Personality. Specifically:
*** Ace is an Achiever (3)
*** Snake an Investigator (5)
*** Santa an Enthusiast (7)
*** Clover a Loyalist (6)
*** Junpei a Challenger (8)
*** June a Peacemaker (9)
*** Seven a Helper (2)
*** Lotus an Individualist (4)
*** Ninth Man is a Reformer (1)
** Junpei and the 9th Man don't use codenames during the game. In a Q&A about the game, Uchikoshi stated that Junpei's codename would have been either Hand, Star (a hand and star have five fingers and points, respectively), or Penta (the prefix for 5), while the 9th Man's codename would have been Pigeon (the kanji for pigeon (鳩) is the kanji for 9 combined with the kanji for bird).
* WordOfGay:
** According to Uchikoshi, [[https://web.archive.org/web/20210514011831/https://twitter.com/uchikoshi/status/359510289558941697 Santa is bisexual]].
** Snake is possibly the first character in history to be confirmed gay [[https://twitter.com/uchikoshi_eng/status/1360856115450241027?s=21 by consensus]].
----