* BadExportForYou:
** When the triple-film DVD came out in 2009, many expected all three movies, including this one, to be widescreen unlike the previous VHS and DVD release. Sadly...no dice. This was later remedied with the upcoming triple feature Blu-ray release in 2016.
** No Western DVD release has included the Japanese version. This is par for the course for ''Pokémon'', but the Japanese version of this movie is in greater demand than the other movies due to its differences from the English version.
* HeyItsThatVoice:
** Mewtwo's Japanese voice actor, Masachika Ichimura, once played Eric in the stage adaption of ''ThePhantomOfTheOpera''. That's right, Japanese Mewtwo is The Phantom. And [[WesternAnimation/TheNightmareBeforeChristmas Jack Skellington]] too.
** In the same version, Shellshocker the Blastoise is voiced by Creator/TesshoGenda - the Japanese dub voice of [[Franchise/{{Transformers}} Optimus Prime]], [[WesternAnimation/BatmanTheAnimatedSeries Batman]], [[Franchise/StarWars Mace Windu]] and [[VideoGame/GodOfWar Kratos]], among others. That's right, they only used him for a couple of lines of PokemonSpeak. But said PokemonSpeak becomes ''[[RatedMForManly awesome]]'' because of him.
* KeepCirculatingTheTapes: This film as well as the latter two movies took years to get a Blu-ray disc release thanks to years of disputes between Warner Bros. (the licensees of the movies for all territories except Japan), The Pokemon Company, Nintendo and Toho. By TheNewTens, fans we're getting irritated over having to deal with the 4:3 aspect ratio of the DVD and VHS releases and pushed for the disputes to end so they could get the films remastered for high definition. The disputes were finally resolved in December 2015, and a Blu-ray disc release of all three movies in a triple-feature Steelbook pack was announced for release in February 2016, in time for the ''Pokémon'' franchise's [[MilestoneCelebration twentieth anniversary]]![[note]]Though there are a couple of catches: First, the films will be presented ''only'' with the 4Kids English dubs in 2.0 lossy stereo sound, and second, all of the special features from the [=DVDs=] will not be available in the set, meaning no Pikachu shorts at the beginning, either[[/note]]
* ThrowItIn: The commentary remarked that Misty's "please, no" reaction to [[spoiler:Ash's death]] was originally, jokingly ad-libbed by Rachael Lillis as [[CallBack "my bike!"]] when trying to find a workable two-syllable reaction to said event.
* UrbanLegendOfZelda:
** There's a rumor circling that Mew in the Japanese version said that the originals were inferior and should perish. According to Meowth (Nyarth in this version) its dialogue was:
-->The real one is real. If they fight only using bodies without skills, the true ones will not be beaten by their copies.
** Granted the actual dialogue still implies that Mew's opinion on the clones was more than a little low.
** Recently, it's been revealed that [[http://www.behindthevoiceactors.com/forums/showthread.php?t=13970 the reports of the death of Mewtwo's original VA]] [[Creator/MarkTwain have been]] [[ReportsOfMyDeathWereGreatlyExaggerated greatly exaggerated]].
*** And he apparently voiced Mr. Fuji as well, instead of Creator/MaddieBlaustein.
* UnintentionalPeriodPiece: The English dub's soundtrack is a nice little time capsule of late 90s bubblegum pop.
* WhatCouldHaveBeen: This film was originally going to serve as the finale to the series, but then the series was renewed and the whole film was rewritten. [[http://www.youtube.com/watch?v=b70GRNYnacI The Japanese teaser trailer]] shows clips from the original planned film.