For some reason I'd heard mixed opinions on Atonement, so wasn't sure what to expect. In terms of performances and film craft (particularly the visual aspects) it's superb. In terms of intensity, the first half is strong, but the second, where it focuses almost entirely for some time on the character of Robbie, seems to lack something. Things pick up again once we're back in London, with the grown-up Briony trying to make amends for her most ill-judged decision back when she was 13, and then there are the final scenes with Vanessa Redgrave playing the elderly Briony, where Redgrave imbues her few minutes of screen time with an intensity that matches the early scenes.
Saoirse Ronan gives an extraordinary performance, the gaucheness matched by the conniving, the stiff body that seems unable to relax, the jealousy that we only understand much later. And Keira Knightley and James McAvoy are solid in their roles. Knightley's role unfortunately diminishes after the first half - she only appears briefly two or three times, and in the war scenes McAvoy is left to play almost to himself; the two accompanying soldiers make little impact. This is the way the screenplay is constructed; I don't know as yet how the book works in this respect (though I'm more tempted to read it after seeing the movie).
Joe Wright seems to be one of those directors who's come out of nowhere. Apart from his recent revamp of Pride and Prejudice, which had some odd moments, (but certainly gave fresh vision to the story) his only work seems to have been in television, and even there, it's been not well-known in general. How did he get to handle Atonement, which obviously has a good deal of money behind it? The lengthy single take on Dunkirk beach is a huge achievement on its own, even though it doesn't add a lot to the story, regrettably. (It competes strongly with the single take in Children of Men.) And it must have used up more than half the film's budget.
About this scene, Wikipedia notes: Charles II: The Power and The Passion, Pride and Prejudice and Atonement all have long tracking shots in them. Atonement has a continuous 4.5 minute shot of the Dunkirk evacuation. "Basically, I just like showing off," Wright told the audience at the Hay Festival. Showing off or not, (or seeing how much he can pack into one shot, like the number of bytes now packed into the average micro sd) the lengthy take is remarkably constructed, and the visual aspects have a painter-like feel about them, something that reflects Wright's art history background.
It would be interesting to re-view the film now that I know how it ends, and know what sort of 'trick' is played on the viewer. I think the acting and visuals would continue to enthrall, and the story might no longer be seen as the main thing. Knowing a great deal more about the characters and where they're headed would actually add to a repeated viewing, rather than take away from it, I think.