What do you want in an adaptation?
There's more debate about this adaptation than I would have thought--I thought it was the best one yet, but there are some comparing it to the 1974 monstrosity. So I'd be interested in finding out what people would want to see in an adaptation of this story, beyond good acting from the performers.
For me, the following elements must be present:
1) Original ending. I can completely understand why Christie changed the ending for the stage play, but we're long past the point where that is necessary. I want the book's ending, not the play's.
2) When it comes to the order of deaths, the why is as important as the who. There's a reason why Tony Marston dies first and Vera Claythorne last. The characterizations of Marston and Mrs. Rogers are particularly important, and they are seldom done correctly, to my mind. Marston has to be less malevolent than he is careless--Mischa Auer, in the 1940s adaptation, to my mind comes the closest to the "ideal" Marston. Likewise, Mrs. Rogers/Mrs. Martino/Mrs. Rodgers/Frau Grohmann cannot be too forceful (Marianne Hoppe, in the 1960s version, misses the mark entirely here).
3) When it comes to the order of deaths, the why is as important as the who. Yes, I know I said that before, but the characterizations of the victims is only half the puzzle. The other half lies in why the characters have been lured to the island in the first place. Every version tampers somewhat with the crimes somewhat, and each one undermines that idea that there are varying degrees of guilt amongst the ten. That's not to say that the screenwriter must slavishly adhere to the exact crimes Christie came up with--each has the right and responsibility to use their creativity to tell the story their way. But there is a world of difference between murdering a child (as Vera does in the original story and in this adaptation) and murdering an adult (as she is accused of doing in every other English-language adaptation), especially when that child has been entrusted to one's care. For me, it is vital that the General's victim be the only one that is not innocent, and that the "final five" be guilty of not just murder but dereliction of duty.
4) Atmosphere. Christie was a master of it, and the perfect adaptation must do her justice. This one, in my opinion, is the first one since the original that does.
5) Play with the rhyme, but don't go overboard. I cannot sufficiently emphasize how happy I am that the "one met a pussycat" line has been done away with, and that the last two adaptations have resisted the temptation to "jazz up" Mrs. Rogers' death by having her "run away" instead of "oversleep herself". On the other hand, the "big bear" line has never been changed, but this adaptation makes it work the most believably (the 1970s version doesn't even bother to try), and does a nice twist on the "bee sting" that I wasn't expecting.
6) If it doesn't conflict with Christie's work, show me something new. Mrs. Rogers' scenes with Miss Brent and Vera in this adaptation are two of the best (in fact, Anna Maxwell Martin is so compelling in every scene she's in that the overall production suffers when Mrs. Rogers is killed off). Lombard and Blore's relationship is more complex than I've ever seen it, and I also like Lombard and MacArthur's scene at the end of Part 1. The cocaine party might be going a bit overboard, but I can at least live with it.
Anyone else? What do you have to have in an adaptation of this story?