* DVDCommentary: By production supervisor John Coates, with clips from interviews with Heinz Edelmann.
* FollowTheLeader: This film was arguably a strong influence on 1974's ''SpaceBattleshipYamato,'' and thus indirectly on ''Franchise/StarWars'', ''Series/{{Battlestar Galactica|1978}}'', and pretty much all of modern SpaceOpera.
* MoneyDearBoy: This movie was made solely because the Beatles were contractually obligated to make a third movie. They learned belatedly that, since this was an animated movie that did not quite star them, it didn't count. They did like it enough to make a short cameo appearance, though.
* RealitySubtext: When the sub's motor breaks down, George comments that he "knows something about motors." He would, as George Harrison's brother was a mechanic.
** The aforementioned ContrivedCoincidence.
-->'''Lord Mayor''': Your faces...
-->'''Paul''': [[MythologyGag They're quite cute, really.]]
** Aged-down Ringo crying "I want me mum!" Ringo was known to be [[MamasBoy very close with his mother]].
* TheOtherDarrin: Peter Batten, the one-time actor who voiced George, was in reality a deserter from the British Army, unbeknownst to the staff of the movie. When he was arrested for deserting, Paul Angelis, the voice of Ringo and the Chief Blue Meanie, stepped in to finish the rest of George's lines.
* ScrewedByTheLawyers: The original home video release in 1987 was pulled after a couple of years due to a lawsuit between MGM/UA and Subafilms (who produced the film) over the rights. Music rights issues were also said to be a factor, as the VHS release lacked the "Hey Bulldog" musical number (though that wasn't in the US theatrical release, either). The parties eventually settled and the VHS was put out again in 1999 via a new restoration, with the "Hey Bulldog" number restored.
* WhatCouldHaveBeen: The remake by Creator/RobertZemeckis, due to [[WesternAnimation/MarsNeedsMoms his previous film's]] [[BoxOfficeBomb poor performance]].
* WritingByTheSeatOfYourPants: The film began production without an ending.