The beginning of the film sets out the conditions on Earth through an introduction to Max and Frey, young orphans. Max promises Frey that someday he will take her to Elysium.
In screenwriting terms, that's a set up for each character, and viewers will expect a payoff for each set up.
But most of the first third of the film is the world building that sets out life on Earth and life on Elysium, with the occasional shuttle of poor people desperately trying to reach Elysium for medical treatment. A security administrator finds herself given a final warning about her job when she deal harshly with the latest illegal attempt to reach Elysium. Because of her methods, she's forced to fire an operative on Earth who recently shot down two of three illegal shuttles.
Those are more set ups for how their situations will be resolved.
Max is hurt and runs into Frey, who is now a nurse with no interest in a poor laborer. She also has a sick daughter who will die unless she gets the advanced medical treatment available only on Elysium.
But so far there's no introduction of a story that will be acted out through Max, there's just the world building and the character introductions and set ups.
What in screenwriting is called an inciting incident doesn't come until later into the film, when Max suffers a lethal dose of radiation and will die in five days unless he can reach Elysium. The plot of the film now has a clear purpose, and a reason for Max to take Frey and her daughter to Elysium, but there's still not a strong sense of a promise for the story. Yes, there's the central idea about the super wealthy moving to a vast gated community (i.e., a space station), but an idea isn't a story.
L.A. Confidential had some wonderful world building for LA in the 50's, and many characters, but it also had a central story about illusion, reality, and identity.
The the climax of Elysium comes, and I understand how it connects to the pieces of the story, I just didn't feel a powerful fulfillment of a story's promise (Max's promise to Frey early in the film to take her to Elysium revolves more around plot than story).
I suspect that because District 9 did so well, the people who put up the money and arranged distribution for Elysium felt they'd get the same payoff, but District 9 had a more central main character on a more clearly defined story journey than Max.
World building is great when done well, and character set ups have a place, but they don't take the place of a well-told story.
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