Missing Critical Aspects of the Book - total spoiler!!

Rating: 7/10 (19 February 2015)

It is no surprise to me, or probably to anyone, that Gone Girl the movie is not as good as the book. First, it is hard to capture on screen what the imagination has created while reading. Secondly, it is hard to recreate in a couple of hours on screen what it takes 6 or more hours to read. It is this flaw that is a given when you adapt a film from a book.
However, my rating is not a reflection of this given, so much as a concern about the overall atmosphere of the film which leaves out some critical aspects of the book. I joke to my friends that Gone Girl is the first book I have read that I loved despite disliking pretty much every character. I don't think this is clear enough in the film.
In the book, the first several chapters are about the disappearance of Amy and the media frenzy surrounding it. This is true of the film as well, but I don't believe it does as good a job of demonizing Nick as is found in the book. Ben Affleck is just too sympathetic in portraying Nick, and you feel the mounting evidence as the trap it is, rather than convincing you he is guilty, as the book does. The appearance of Amy in the book is quite shocking, whereas it is not so much in the film. This is one of the aspects of the book that made it so popular - you are convinced in the beginning that it is likely Nick killed Amy and is covering it up. The film just does not give you this feeling.
Another flaw in the film is the portrayal of Amy's parents. It is so very clear in the book that Amy has been used by her parents all of her life. She has been a disappointment to them because she never lived up to their ideal of her as Amazing Amy. They are a totally selfish couple, in the book, that use Amy's disappearance as a way to further their own ends - and it helps their books to sell again. They have selfishly stolen her home and her trust fund, leaving her and Nick in a difficult situation. Their selfishness and use of Amy does not come off in the movie at all. They appear to be media savvy parents who are using their fame to aid them in finding Amy, when it is the opposite in the book - they are using Amy's disappearance as a way to push their own agenda and for self- promotion. In the book, these are not nice people. The movie just slides over their selfishness as a sort of "oh well". But, this is a critical factor to explain Amy's actions, especially at the end. Did anyone notice that Amy goes back to Nick and just blows off her parents? In the book, you know why.
Another critical aspect of the book that is fairly weak in the film is the relationship of Amy with Desi (Neil Patrick Harris). This is a wealthy man who has always been obsessed with Amy. Amy turns to him in her hour of need and he is thrilled to assist her. This is where the film falls flat - in the book this relationship almost immediately becomes sinister. Desi is not simply taking care of Amy and protecting her, he has her caged in his lake home without any ability to get out. She does not have access to a car, she cannot use a phone, she cannot use the internet, and the entire property is locked and inescapable. In the book, Amy has become desperate and is looking for any way she can escape Desi's entrapment of her. The action taken against Desi is the act of a desperate woman who sees no other way out of her predicament. In the movie it appears much more cold-blooded. In the book she is desperate to escape Desi and return to Nick.
Finally, the ending of the book and the ending of the film are the same, but the motivation is not clear in the film. So many people say they hate the way the movie ended. Well, that is because it is not made clear that regardless of how sick their relationship may be, Nick and Amy have always found that the other pushes them to be the greatest they can be and their lives would be boring without each other. Nick and Amy both reach this conclusion, and it is not just another of Amy's traps, as it appears in the film.
The film of Gone Girl makes Amy appear even more despicable than in the book, while glossing over the egregious actions of the other major players. This was the strength of the book. The film is good, but it just does not incorporate this total sense in the book that everyone gets what they deserve.