* ActingForTwo: Candy Clark plays both Mary-Lou and the wife Thomas left behind. This isn't obvious because the latter is a RubberForeheadAlien who has no dialogue. (She also played Thomas himself in one scene, with a hat pulled over her face, when David Bowie was ill.)
* ActorAllusion: [[WebVideo/BrowsHeldHigh Oancitizen]] put it best (to the tune of [[Film/{{Labyrinth}} "Magic Dance"]]):
--> ''Now, [[Music/DavidBowie Ziggy Stardust]] was an alien on Earth''\\
''And he was doomed''\\
''To fall to human vice, and leave his people blue''\\
''Director knew!''\\
''Nicholas Roeg must have known 'bout this''\\
''Banned from space, this is a case''\\
''Of casting your actor... based on his works!''
* BadExportForYou: The original US distributor cut 20 minutes from the film, rendering it even more confusing. They were restored in the 2011 re-release.
* TheCastShowoff: Amusingly {{subverted}}; Newton is a ''terrible'' singer!
* PlayingWithCharacterType: Music/DavidBowie started getting film offers almost as soon as he had his commercial breakthrough via his AlterEgoActing persona of Ziggy Stardust, a flamboyant alien (or TouchedByVorlons) rock musician, MessianicArchetype, and TragicHero who succumbs to SexDrugsAndRockAndRoll, ego, and his own fans. But virtually all of the roles he was offered were Ziggy expies. He was drawn to the character of Newton because he ''wasn't'' an {{Expy}}. Yes, Newton is also an alien MessianicArchetype TragicHero...but he's TheStoic, {{Moe}} before Moe was trendy, and his succumbing to Earthlings and their vices comes not from success going to his head but because HumanityIsInfectious.
* RealitySubtext: Bowie was addicted to cocaine and other illicit substances at this point in his life, so seeing him play a character who falls under the sway of substance abuse has this trope written all over it (indeed, the filmmakers were aware of this). Perhaps fittingly his albums ''Station to Station'' (1976, recorded at the lowest point of his addiction) and ''Low'' (1977, the first album of the "Berlin Trilogy" that unfolded as he gradually emerged from it) got their cover art from photos of him here. As well, the look and to a lesser extent personality of his Thin White Duke stage persona for the former album and tour was adapted from his work here.
* ReclusiveArtist: Newton definitely counts--he rarely goes out in public and leaves the day to day operations of the company to Farnsworth. {{Justified}} as he wants to escape detection ("My life is not secret, but it is private.").
* UnintentionalPeriodPiece: The story supposedly takes place over several decades, but the fashions, technology and virtually everything else remain pure 1970s. This isn't helped by the fact that WeAreAsMayflies to an AlienAmongUs hero who isn't physically aging, meaning that only the appearances of the supporting characters clue us into the passage of time. On top of that, just the fact that Music/DavidBowie plays an alien clearly dates it as in the decade of his Ziggy Stardust sci-fi glam phase (by the time the film was shot in 1975, he had already moved on from that persona and sound).
* WhatCouldHaveBeen
** Creator/PeterOToole was originally cast as Newton.
** The novel was primarily set in Kentucky, but the movie used New Mexico to take advantage of a tax break for British filmmakers (this was the first British-produced film shot entirely in the U.S.). Its deserts also provided a useful backdrop for the scenes set on Newton's home planet.
** Bowie originally was tapped to write the score and worked on it with Paul Buckmaster. For various reasons, it wasn't used and has never been formally released, though a backwards bass part on ''Low'''s "Subterraneans" was taken from what they worked on.
** Roeg also thought about casting Creator/MichaelCrichton as Newton. While that didn't work out, it ''did'' lead Roeg to start thinking about making the film a NonActorVehicle.