The production had some big problems (Theron got a major neck injury while performing stunts), and there's no telling how that could've affected the final product. It's hard to believe the movie would be any less boring if Theron had been physically able to perform a few more wire flips or high kicks. The problem with the movie isn't just with the action sequences (which are mostly poor). Scenes where people are talking to each other are maddeningly slow-paced.
Director Karyn Kusama has instructed her performers to over-annunciate at lethargic speeds, making the most simple phrases sound like Shakespeare on Quaaludes. This film screams for a crisper tone. Sure, a couple of slowed-down moments can work in any film, but every time characters speak to each other in this movie, they seem to be on the verge of big naps. The worst offender is Marton Csokas as one of utopian leaders. He acts as if he's rehearsing Hamlet at 4:30 a.m. after a two-day bender.
The plot is a potpourri of third-rate science-fiction films. The world has been mostly killed off by some sort of virus, and survivors are living in an atoll that keeps Mother Nature out and virus survivors in. The synthetic society has existed for more than 400 years, and a band of rebels called Monicans looks to overthrow their leaders because they are clearly bored out of their minds. The movie's big-twist ending is hardly surprising, a gimmick that is being recycled over and over again at the cinema (ironic, since it involves cloning).
As for Flux, her dreaded fighting arsenal includes flash-cheat-editing, the extreme action close-up that makes who's hitting who impossible to decipher. Of course, the arsenal also includes the impenetrable running-away-really-fast, which is sometimes enhanced by slow motion. If somebody is running away really fast, yet in slow motion, it's a sure guarantee that their butt will remain unscathed by an enemy's bullets. Unless you're Marton Csokas ... his ass gets pegged multiple times.
Theron isn't the only talent being wasted. The great Frances McDormand is given the worst hairdo in cinema history and instructed to, of course, speak very slowly. McDormand is a beautiful actress, but she should get on the phone with her agent with a "no more harsh lighting, and no more frizzy orange hair!" proclamation. She actually fares better than Pete Postlethwaite, who's saddled with terrible age makeup and a goofy space suit that doesn't flatter his figure.
As bad as the film is, there are a couple of decent action scenes. When Flux attempts to board a blimp-like floating monument, it's almost exciting. A sequence where Flux must outwit a security system that has knife-sharp blades of grass is fairly interesting. The filmmakers should've gotten their actors to shut up and inserted a few more zippy moments to move this thing along.
Theron was having a good year (her work in North Country is quite solid). Her performance in this one is probably the film's best, but that's not saying much. While she doesn't have the makings of a wallet-padding franchise on her hands here, it's doubtful it will harm her career. This debacle isn't nearly as damaging as, say, Catwoman, which had no redeemable value whatsoever. Aeon Flux has spots of interest but, for the most part, it's just a withering sci-fi clone.