[[caption-width-right:350:Ahhh, the Eighties. Those were the days...]]

->''Buildings 250 stories high!…traffic on nine levels…rockets that shoot from star to star…airplanes that land on the roofs of buildings…a whole meal in a capsule that can be swallowed in one gulp… No -- this isn't a Jules Verne dream induced by a Welsh rarebit. It's New York in 1980, as foretold in the new Fox picture, "Just Imagine!"''
-->-- '''''Photoplay''''', November 1930

A big-budget ScienceFiction musical comedy film from 1930, featuring the most impressive special effects seen up to that time. The animated model of NewYorkCity was large enough to fill a zeppelin hangar and cost a quarter million dollars to build -- and this during the Great Depression!

Unfortunately it was a complete flop.

In the distant future of 1980, marriages must be approved by the courts, based on ones' value to society. J-21 (John Garrick) can't get permission to wed the beautiful LN-18 (Maureen O'Sullivan), as his rival, the wealthy and arrogant MT-3 (Kenneth Thomson), is more socially prominent. J-21 appeals the decision and is given six months to distinguish himself. As scientist Z-4 (Hobart Bosworth) has just invented a "Rocket Plane" spacecraft, J-21 volunteers to be the first man to fly it to Mars. His [[FishOutOfTemporalWater anachronistic]] friend Single-0 (El Brendel) stows away on the InterplanetaryVoyage in order to provide PluckyComicRelief.

Not related to [[ComicBook/JustImagineStanLeeCreatingTheDCUniverse the comic series by]] Creator/StanLee.
!!The film has the following tropes:

* AliensSpeakingEnglish: Averted, as communication with the Martians is done via pantomime and body language.
* BureaucraticallyArrangedMarriage
* CampGay: The Martian king.
-->"She's not the Queen -- he is!"
* CatchPhrase: "Give me the good old days."
* ColdSleepColdFuture: Single-0 pines for "the good ol' days" when [[FoodPills food didn't come in pills]], and babies from coin-operated vending machines.
* EternalProhibition: The persistent rumor that Prohibition was going to be repealed 'next year' is spoofed by the fact that it's still going in 1980 (and still rumored to be on the verge of repeal). Note: Prohibition was repealed in 1933.
* ExtyYearsFromNow: The BigApplesauce, fifty years on.
* EvilTwin: Mars has an entire race of these.
* FishOutOfTemporalWater: A man in the present day (e.g. 1930), played by vaudeville comic El Brendel, is killed by lightning on a golf course, and revived by scientists fifty years later purely as an experiment. They give him the name Single-0 (Brendel's standard character was named "Ollie"), then forget about him. Fortunately the kind-hearted J-21 is there to take Single-0 under his wing.
* FlyingCar: Everyone has their own personal airplane, all [[{{Zeerust}} propeller driven]]. They have [[FutureCopter horizontal props inset in each wing so they can hover in midair]], allowing their occupants to chat or burst into song.
* FoodPills
* GoodOldWays
* GreenSkinnedSpaceBabe: [[UsefulNotes/{{Mars}} The Red Planet]] is populated by scantily-clad showgirls in [[SpaceClothes glittery outfits]] doing {{Busby Berkeley Number}}s.
* LoveTriangle: J-21 and MT-3 vie for the affections of the comely LN-18.
* NoNewFashionsInTheFuture: Women wear reversible clothes and [[WeWillNotHavePocketsInTheFuture men's suits have only one pocket]].
* PunnyName: Most of the character names are puns of real names and words, such as J (Jay), LN (Ellen) and MT (Empty). An explicit joke is made of the name "U-2" being confused for "you, too".
* RetroRocket: The Rocket Plane.
* SpaceClothes
-->"The Martian costumes could start new fashion trends if this got widely shown. Lightning bolts, spikes and metallic print bikinis mixed with ridiculous wigs and eye make-up are part of the wackiest outfits in film history." (Michael Weldon).
* TakeThat: In a jab at Henry Ford's anti-Semitism, all the flying cars are made by Jewish manufacturers.
* VideoPhone
* WeWillNotHavePocketsInTheFuture: The only pocket on men's clothing is [[EternalProhibition for their hipflask]].
* YouAreNumberSix: In the future people have alphanumeric codes instead of names.
* YouNoTakeCandle: This was part of Brendel's comic routine -- he billed himself as "The Synthetic Swede".
* {{Zeerust}}: New York is the standard MegaCity with [[FuturisticSuperhighway multi-lane elevated roadways]], [[LayeredMetropolis suspension bridges hung between towering megastructures]], and personal aircraft buzzing from building to building. Transoceanic airliners are dirigibles. One prediction they get right is that paper towels will be replaced by hot air dryers.