Look at the differences between the movie Eragon and the book by Paolini. Explore why the book was a relative success but the movie was such a cinematic flop. Areas to explore might include character development, major battles, what was changed and perhaps why (such as trying to keep the rating they wanted).
Adaptation Theory can help immensely with this essay. Linda Hutcheon has a seminal text on the topic. – WALSTIB9 years ago
It could also be interesting to do a general article about where book-to-movie transitions often fail, and use Eragon as a framing device, since it sadly falls victim to many of the pitfalls. I would personally attribute many of the problems in Eragon specifically to an attempt to condense the entirety of a very long and complex book into a single movie; the entire thing felt incredibly rushed. – Connor Gregorich-Trevor9 years ago