DISCLAIMER: This post contains references to events in both the movie and the books. I recommend reading and watching Scott Pilgrim before reading this post. All links are affiliate links. You have been warned.
I recently both read the Scott Pilgrim graphic novels and watched the movie. The similarities are stunning, but the differences seem pointlessly disappointing. Whenever someone tries to adapt a given medium into a movie, the tendency is to start off strong and a lot like the original, but then to take artistic license and totally change it at the end of the movie. I know part of this is shortening the story in order to fit in the new format, but filmmakers tend to use adaptation as a platform for creation.
The question is, is this a good thing or bad thing? On one hand, you're creating a new medium for the fans of the original, but on the other hand, it's a new medium for new fans. To what extent is it fair change the original story to fit a new medium for the sake of gaining new fans? Is it just that the old medium didn't appeal to people who are now becoming fans of the new medium? Some people are just turned off by the concept of graphic novels (i.e.: comic books). Others dislike the time investment of any sort of novel, and are much more inclined to watch a movie which is easier and shorter. Even a graphic novel runs long (Scott Pilgrim in particular fills six books) compared to a movie which generally fits into two hours of screen time.
There are exceptions, of course. This is not to say that Scott Pilgrim is a classic in the same way, but if Peter Jackson had taken that much license with Lord of the Rings, fans of the original would've been appalled. What Tolkien fans were looking for was a visualized version of the amazing world that he created with words. The goal then was to fit Tolkien's vision into a watchable screen format without losing its original spirit. Of course, the books had existed long enough to have enough fans to support a budget that gave the filmmakers enough screen time—4 to 5 hours per film—in order to make this a reality.
Scott Pilgrim, of course, doesn't have nearly the fan base and so the question remains: why change the second half of the story so much from the original? The remarkable thing about this movie is that it so perfectly matches the graphic novel for about the first hour. After that point it starts making respectable cuts of scenes that arguably might have been unnecessary even in the novel. After some creative shuffling of the important plot points in the main body of the movie, the filmmakers made some choices that, I believe, diverged from the original story.
The most tragic thing about the movie is that the filmmakers and entirely missed the point of Nega-Scott. This concept isn't even fully developed in the novels, but even though it was subtle, it seems to me that the author was trying to say how Scott forgot his mistakes because he ran away from his dark side. In either killing or fleeing from his dark side, Scott also avoided absorbing the lessons from the experience. In the novels, Scott's training session with Kim leads him to eventually meld with Nega-Scott to become a whole person, capable of defeating Gideon and fixing his relationship with Ramona. In the movie, however, they seem to make a kind of flippant joke of the character.
All of this is not to say that the movie Scott Pilgrim vs. The World, is not thoroughly enjoyable on its own merit. It just simply does not contain the same depth as the graphic novels.
Is it impossible to maintain the depth while condensing the story into 120 minutes, or is it just REALLY HARD to do? I don't think it's impossible, and if I'm right, then this hard work is where the value is created. Interestingly, this means that it is actually harder (and therefore more artistic) to do a great job of condensing the exact story, than it is to create a new story out of the old one.
A movie with this kind of condensed depth kicks you in chest—and leaves you wanting to know more. If you're truly a new fan, you'll go to the original material for more. There is no point in using an original story to create a disconnected movie that is easier to swallow than the original. Condensed means potent. If you want to create art, never fear scaring away those that can't handle it.