* ActingForTwo: In ''The 2nd Runner'', Jehuty's and Anubis' A.I., ADA and DELPHI, share the same voice actress. Cynthia Marcucci and Yoshino Miki are their English and Japanese voice actresses, respectively.
* DevelopmentHell: The Enders Project, the ''Zone of the Enders: The 2nd Runner'' sequel has been put on hold and has yet to resume.
* FanNickname: The [[CompilationRerelease HD Collection]] has coined "UsefulNotes/HighDefinition [[HumongousMecha Robot]] {{Action|Game}}" by the Zone of the Enders: The Unofficial Site as a play on ''The 2nd Runner''[='=]s TagLine.
* TheMerch: Aside from the games and anime, there are wall scrolls, soundtracks, art books, and other products. Special mention goes to the Toys/{{Revoltech}} figurines of Jehuty, Anubis, and the Vic Viper, as well as Kotobukiya's line of model kits.
* NoExportForYou: Prior to HD Collection's version of ''Zone of the Enders: The 2nd Runner'', a [[UpdatedRerelease Special Edition]] of game was released in Japan and Europe, but strangely never to North America. The Special Edition featured some graphical and frame-rate improvements over the original game, new difficulty levels[[labelnote:*]](the Japanese version has an Extreme difficulty and a Super Hard difficulty in-between [[HarderThanHard Very Hard]] and [[NintendoHard Extreme]] mode, whereas the European version only gets the Extreme mode)[[/labelnote]], new cutscenes and battle sequences, an expanded Extra Mission mode, and sub-weapon tutorials for the VR Training. This changed though as the HD Collection includes the European version of the Special Edition of ''The 2nd Runner'' for the North American release.
** And there's the two [[LimitedSpecialCollectorsUltimateEdition premium editions]] for the Japanese version of ''Zone of the Enders HD Edition'', which has ''two'' books instead of one from the overseas release, and a Blu-ray re-release of the ''[[TheAnimeOfTheGame Zone of the Enders: 2167 IDOLO]]'' [[OriginalVideoAnimation OVA]] with the most expense of two packages.
* OldShame: Whilst not necessarily ashamed of the original game, the HD Collection's pre-release hype was all focused on ''The 2nd Runner'', with barely a word being said about the HD remastering of the original game; on top of that, the intro specially made for the HD Collection only focuses on the original game for roughly a minute and a half, with the remaining four minutes focusing on ''The 2nd Runner''.
** To make things even worse, the Hexa Drive patch on the [=PlayStation=] 3 version only addresses the frame-rate issues of ''The 2nd Runner'' and enhanced its visual quality to 1080p; the original game is left untouched. Granted the original ''Zone of the Ender''[='=]s frame-rate wasn't as botched as its sequel, High-Voltage Studios only enhanced the games for 720p when these games were supposed to be in 1080p.
* PreviewPiggybacking: The first ''Zone of the Enders'' was widely known for its inclusion of the highly-anticipated ''VideoGame/MetalGearSolid2SonsOfLiberty'', which was the biggest reason many ''Metal Gear Solid'' fans bought the game. History repeated itself in 2012 with the HD Collection of the series, this time bundling a demo of ''VideoGame/MetalGearRisingRevengeance''.
* SameContentDifferentRating: Both ''[=ZoE=]'' games on the Playstation 2 received M for Mature ratings in the US, despite having precisely one bloody scene each between the two of them, no profanity, and no sexual content. When the HD Collection came out in the US, the version without the Metal Gear Rising demo received a somewhat-more-sane Teen rating.
* {{Vaporware}}: The [[UsefulNotes/PlayStationVita Playstation Vita]] version of the Zone of the Enders HD collection has been [[https://www.youtube.com/watch?v=XqVI4P6I3JQ announced]] at the Tokyo Game Show in 2011 and no word has been said regarding it since.
* WhatCouldHaveBeen: Several design sketches show unused designs for some of the frames. For example, the Raptor was initially supposed to be dual-wielding katana-like weapons, instead of having them grafted on to their arms; as well as unused names for most frames, if the HD Edition's Special Art Book is to be believed, at least. For example:
** ''Jehuty'' went through several name changes, from ''New Eden'' to names such as ''Exodus'', ''The Whisper'', ''Vision Divine'', ''Lightning'' and ''[[OddNameOut Megadriver]]''.
** Similarly, ''Tempest'' had the names ''Faust'', ''I-Vanvo'', ''Epusutain'', ''Vadourv'', ''Devionario'', ''Manonresco'' and ''Volpone'' before settling on Tempest.
* [[MarthDebutedInSmashBros Z.O.E's Music Debuted in Metal Gear Online]]: Some music from ''Zone of the Enders''[='=] soundtracks was reused in [[Franchise/MetalGear Metal Gear Online]]; most notably "Vivid Transparency", [[http://www.youtube.com/watch?v=8N6_mGzAvm0 heard here.]] This has led to a surprisingly large number of people wondering where someone got the notion that a ''Metal Gear'' track is from this game about flying, sword-fighting robots.
----