- Adaptation Displacement: Nobody has heard of the book (Make Room! Make Room! by Harry Harrison), but most people have heard about the movie, or at least "It's people! Soylent Green is people!" Which, incidentally, isn't in the book—it's just a straight-up Crapsack World.
- All There Is to Know About "The Crying Game": That Soylent Green is people is generally known — and that knowledge brings some folk to the film. The big reveal ain't gonna work for them, but watching the various characters slowly learn the secret is a very interesting and emotional journey in its own right. Also less known is that the world's oceans have been utterly exhausted.
- Alternate Character Interpretation: Soylent Corporation. Corrupt corporation or doing what's necessary to keep civilization afloat?
- Anvilicious: If we don't do something about the overpopulation, we're all going sleeping shoulder to shoulder in the streets and stairwells, until we're turned into green biscuits!
- Keep in mind that the movie was made in the '70s. Birth control had only been legal for a few years, and nobody took environmental protection seriously. You could argue that this movie was a well-needed slap in the face. A self-defeating prophecy, perhaps?
- Soylent Green is very similar to its contemporary Drifting Classroom, which featured very similar themes. It came out in 1972's Japan and proposed that humanity would drive itself into extinction through pollution and overpopulation before the year 2000, destroying the environment in the process. Both works have valid concerns, that overpopulation and pollution are huge problems, but neither issue went in the direction they predicted.
- There's also the fact that at the time the book was written, people didn't realize just how much food production was going to explode with the Green Revolution. There's a reason mass starvation only really happens due to transportation issues now, we grow enough food to feed 12 billion people currently and the systems we have in place make it so that those numbers have no reason to go down.
- Fridge Horror: Lots of it.
- Funny Moments: A few during the dinner scene, such as Thorn eating a leaf of lettuce and shrugging as if to say "I don't see what the big deal is."
- Harsher in Hindsight: Roth's suicide. The actor playing him, Edward G. Robinson, was dying of cancer. Only Charlton Heston knew. And because of this, Heston's tears were real.
- Hilarious in Hindsight: Since 2013, there is now a dietary supplement company called Soylent. The company's founder chose the name for this reason.
- Heartwarming Moments: The dinner scene, when Thorn is treated to real food and uses a proper metal fork and knife.
- It Was His Sled: Soylent Green is people. Like "it was Earth All Along", it's now possibly the world's most poorly guarded secret and has been parodied almost universally in Sci-Fi comedies and plenty of other places, too.
- Memetic Mutation: "Soylent Green is people!"
- Nightmare Fuel: "Soylent Green is people!"
- The scoops are pretty unpleasant. Imagine Trash Trucks converted with Bulldozers designed to scoop up the rioting populace. On the outside, it seems like an important safety feature. However, after the twist ending was revealed, it seemed that Thorn's prediction of the people being used as cattle came true.
- The setting itself. The oceans are dying. The literal source of life on Earth is almost gone! This isn't a dystopia story anymore; this is a mass extinction event! The humane thing at this point would be to just make a Mercy Kill for the whole species, because there's no recovering from this. The existence of the euthanasia clinic(s) implies the governments of the world know this in-universe, too.
- People are eating Soylent Green, right? Then they die, and their bodies are processed into Soylent Green, eaten by people who die and are processed...
- Squick: Depending on your squeamishness. The processed human flesh really doesn't resemble meat anymore, it's just a wafer of protein. At that stage, it's pretty academic.
- Strawman Has a Point: The nature of Soylent Green is certainly ghoulish, but it is literally the only resource left; the populace has a Sadistic Choice of either cannibalism or mass starvation. Well, you know what they say; "Any option is preferable to extinction." Of course, one can also interpret that Charlton Heston's character was horrified by realization of that horror in his famous "Soylent Green is people".
- Values Resonance: Overpopulation, pollution, and climate change are still hot topic issues today. Let's all hope this film doesn't retroactively turn into a documentary.
YMMV / Soylent Green