There are definitely big talking points the film explores, which elevates this as a pointed piece of dystopian science fiction. The depressing vision of an overpopulated world is a gritty and grim prediction as it is, and even though we aren't eating little colored squares just yet, some issues remain prevalent today. The biggest and most impressionable scene might be the one where dumptrucks plow into rioting crowds and scoop up dozens of human beings into their hoppers.
This is a detective story first and foremost though, so all these world-building elements are intrinsically entwined with the mystery that Thorn unravels. The film moves at a fair pace, balancing the occasional slice-of-life scenes and melodrama with sudden bursts of interrogations, chases, and fistfights. The film achieves a rhythm between tension, mystery, and shocking revelations. While most of this appears to be lifted from the original novel (Harry Harrison's Make Room! Make Room!), filmmakers twisted the story so that it ends, and ultimately hinges on, Soylent Green and its horrendous secret. Chances are that the final reveal might have been spoiled for you already, but even with that knowledge, there is a sobering tragedy in watching the characters discover the truth and all its dire, nihilistic implications. You know things are bad when people who know the truth just want to die (corporations have even made it easy to die via institutionalized euthanasia, leading to one of the film's more pleasant sequences, which sends off one of the most lovable characters off on a bittersweet note).
None of this is as mind-blowing as Planet of the Apes or as action-packed as The Omega Man, but Charlton Heston still exudes grit and machismo in the lead role. In this sci-fi trifecta, Soylent Green is easily the film with the most gravitas, largely because of how grounded it is. So grounded that it might look dated to modern eyes. There's no escaping the sheer amount of kitschy 70s paraphernalia that ordains each scene (not to mention the costumes, which range from drab work garments to flashy colored robes). I couldn't help but to notice that some scenes look built from cheap materials, like bubble wrap for a transparent sliding door, or crinkled plastic for a shower curtain. I can't tell if this is an intentional way of showing how desperate this world is, or if it's just a production shortcut. Cinematography is not particularly pretty--the film is constantly awash in hazy gray, brown, green, and yellow hues as the camera focuses on drab locations. Camera work and editing have a standard, workman quality that lets the ugly world speak for itself. The flashiest scenes occur in the opening montage, which is a kind of photographic slideshow with music, but even this comes across as a product of the 70s. Music is rarely a standout. Sound quality is good for its time, with maybe a few scenes where unusual sound effects emphasize the sci-fi setting.
Despite the limitations of the production and the time it was made, the film is built from a functional script that successfully combines all the necessary elements (the world-building, the detective story and all its tension, the sobering critique on society) into a cohesive package. The cast shows fair talent--when Heston isn't beating people up and outrunning corporate assassins, he spends some time hanging out with his buddy Sol--Edward G Robinson's final role, for which he brings an amiable personality and wisdom that makes his character shine through the story's cynicism. Other performances aren't terrible, but not quite as memorable as Heston or Robinson--I'd peg Brock Peters and Paula Kelly as the next best performances worth noting.
This is a rather ugly film, and it's hard to look past its dated production quality. But these aspects ultimately contribute to a grim and depressing picture of the future. The story alone, with its grim and memorable twist, makes Soylent Green a classic picture to my eyes. An easy recommendation to all sci-fi fans.
8/10