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!"A big budget Science Fiction musical comedy, featuring the most impressive special effects seen up to that time. The animated model of New York was large enough to fill a zeppelin hanger 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 can't get permission to wed the beautiful LN-18 as his rival, the wealthy and arrogant MT-3, is more socially prominent. J-21 appeals the decision and is given six months to distinguish himself. As scientist Z-4 has just invented a Rocket Plane (e.g. spacecraft) J-21 volunteers to be the first man to fly it to Mars. His anachronistic friend Single-0 stows away on the Interplanetary Voyage in order to provide Plucky Comic Relief.
— "Photoplay", November 1930
The film has the following tropes:
- Aliens Speaking English: Averted, as communication with the Martians is done via pantomime and body language.
- Bureaucratically Arranged Marriage
- Camp Gay: The Martian king."She's not the Queen — he is!"
- Catch Phrase: "Give me the good old days."
- Cold Sleep, Cold Future: Single-0 pines for "the good ol' days" when food didn't come in pills, and babies from coin-operated vending machines.
- Eternal Prohibition: The persistent rumor that Prohibition was going to be repealed 'next year' is spoofed by the fact that it's still going in 1980 (and still rumored to be on the verge of repeal). Note: Prohibition was repealed in 1933.
- Exty Years from Now: The Big Applesauce, fifty years on.
- Evil Twin: Mars has an entire race of these.
- Fake Nationality: El Brendel, who plays the Swedish Single-0, wasn't actually Swedish.
- Fish Out of Temporal Water: 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, then forget about him. Fortunately the kind-hearted J-21 is there to take Single-0 under his wing.
- Flying Car: Everyone has their own personal airplane, all propeller driven. They have horizontal props inset in each wing so they can hover in midair, allowing their occupants to chat or burst into song.
- Food Pills
- Good Old Ways
- Green-Skinned Space Babe: The Red Planet is populated by scantily-clad showgirls in glittery outfits doing Busby Berkeley Numbers.
- No New Fashions in the Future: Women wear reversible clothes and men's suits have only one pocket.
- Punny Name: Most of the character names are puns of real names and words, such as J (Jay), LN (Ellen) and MT (Empty).
- Space Clothes"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).
- Take That: In a jab at Henry Ford's anti-Semitism, all the flying cars are made by Jewish manufacturers.
- We Will Not Have Pockets in the Future: The only pocket on men's clothing is for their hipflask.
- You Are Number 6: In the future people have alphanumeric codes instead of names.
- You No Take Candle: This was part of Brendel's comic routine — he billed himself as "The Synthetic Swede".
- Zeerust: New York is the standard Mega City with multi-lane elevated roadways, 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.