((Many thanks to the people who sent me copies of this article, after I failed to keep one and Google lost it.))
(More catching up on posts I should have made a month ago. I can just about remember what I meant to say...)
Obvious note; the problem with commenting on this movie is that it's hard to do so without spoilers. And it's honestly good enough not to deserve that.
But, okay, the reviews and trailers have (unavoidably) given away a bit. Not everything, though; a certain amount of layered revelation is part of this film's charm. It's widely described as a time travel story, but what emerges fairly early is that this isn't quite true - or perhaps it is, as it turns out. Choose your own definitions. More annoyingly, a lot of comments seem to describe it as complicated or hard to follow, which suggests to me that too many people's brains just shut down when they're confronted with skiffy ideas about time or any kind of game with causality, because I really didn't see much complexity at all. The explanation of how things seemed to work, and eventually of the film's conclusive twist, struck me as very straightforward, even linear, even if the protagonist did replay the same few minutes of apparent time repeatedly as he went along. Nor was the film quite as rigorous as comments suggested; several of the eight-minute replays that were necessary to the plot would have been too repetitive for any audience, and so were skimmed over.
(Anyone who finds this film unpleasantly hard to follow really, really needs to avoid Primer, by the way.)
In fact, the relatively rigorous approach to plot logic made this a true science fiction story (as opposed to "heroic fantasy in space" or "action thriller with extreme special effects", which is what Hollywood tends to mean by "science fiction" these days), and with Source Code following on Moon, it seems that director Duncan Jones has a genuine and fairly unusual interest in the genre. This isn't hard SF, mind; the core idea of the plot is handwaved fairly frantically, involving as it does multiple scientific and technological jumps far beyond anything that could be made to look hard-SF plausible in the modern-day setting.. In the end, it's using the word "quantum" a lot to justify a fairly arbitrary story with a large dose of wish-fulfilment, even if one could argue that what it does is opt for the Many-Worlds interpretation of quantum mechanics without being so crass as to say so (or to even mention Schrodinger's cat).
Nor is the plotting entirely immaculate; looking back over the film, one can identify significant unanswered questions of both logic and morality. (What could one say about the fate of the original occupant of the body which the hero borrows, for a start?) Still, it is a film about an idea, even if that idea is a bit shaky.
The cast, by the way, are good, and the leads are given enough to get their teeth into. Jake Gyllenhaal makes an effective hero, confused and stressed, far from infallible but ultimately capable enough; Michelle Monaghan is an attractive overt object of desire; Vera Farmiga really carries the film, balancing professionalism with sympathy. Only Jeffrey Wright really has a problem - not that the actor isn't fine, but his character seems unfairly treated. He's vain and unsympathetic, to be sure, but I couldn't help feeling that a man who invented such mind-bending technology would have the right to a very large dose of vanity indeed, and even if that is his main motive for employing it and exploiting the hero, he is actually trying to save thousands or millions of lives in the process. Making the scientist into something of a villain, with silly physical preening to match his intellectual hubris, was the one place where this turned into cheap, bad Hollywood SF.
But if that's the one place, well, we can't complain too much, can we? This isn't the film of the year - probably not even the SF film of the year - but it's a film that I could wish a lot more films were like.