- Acting for Two: 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.
- Development Hell: The Enders Project, the Zone of the Enders: The 2nd Runner sequel has been put on hold and has yet to resume.
- Fan Nickname: The HD Collection has coined "High Definition Robot Action" by the Zone of the Enders: The Unofficial Site as a play on The 2nd Runner's Tag Line.
- The Merch: Aside from the games and anime, there are wall scrolls, soundtracks, art books, and other products. Special mention goes to the Revoltech figurines of Jehuty, Anubis, and the Vic Viper, as well as Kotobukiya's line of model kits.
- No Export for You: Prior to HD Collection's version of Zone of the Enders: The 2nd Runner, a Special Edition of the 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* , 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.
- Old Shame: 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. Another remaster of 2nd Runner was also developed for VR while the original Zone of the Enders gets left behind.
- Preview Piggybacking: The first Zone of the Enders was widely known for its inclusion of the highly-anticipated Metal Gear Solid 2: Sons of Liberty, 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 Metal Gear Rising: Revengeance.
- Promoted Fanboy: Yoji Shinkawa, the series's mecha designer, grew up playing Gradius and always envisioned the Vic Viper's two protruding front segments as legs on a Transforming Mecha. He leapt at the opportunity to see this vision come to life when he included the Vic Viper in The 2nd Runner as Leo's mech.
- Same Content, Different Rating: 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. Similarly, the PS4 and PC re-release of the second game, having no connection to Metal Gear, has a T rating.
- Vaporware: The PlayStation Vita version of the Zone of the Enders HD collection has been announced at the Tokyo Game Show in 2011, and no word has been said regarding it since.
- What Could Have Been: 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 Megadriver.
- Similarly, Tempest had the names Faust, I-Vanvo, Epusutain, Vadourv, Devionario, Manonresco and Volpone before settling on Tempest.
- Z.O.E's Music Debuted in Metal Gear Online: Some music from Zone of the Enders' soundtracks was reused in Metal Gear Online; most notably "Vivid Transparency", 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.
Trivia / Zone of the Enders