And my fears were completely unfounded. It was a fantastic adaptation of the novel, and despite a few major changes to make the novel fit into a movie format (substituting characters, not going down some major plot arcs, some stylistic changes, and rushing through some parts), it was a really, really good movie with fantastic casting, good acting, and some jaw dropping special effects, and remarkably, a lot of the themes from the novel were kept intact, which is pretty damn remarkable. I was also surprised at the set and costume design, which were honestly almost exactly what I imagined them to look like back when I first read the book back in grade 7, which was a long motherfucking time ago (I'm 25 now, to give you an idea).
My only two (non-spoilerish) complaints were that I think the movie could have been about half an hour longer to flesh out Ender's time in Battle School, especially since they only show two battles in the movie without doing anything to show the armies Ender's in or commanding actually taking part in more than the two, as well as showing how Ender actually changed how the game was played. It was kind of jarring that the first battle was the first battle in the books, and the last one was the last one, which really showcased how much pressure and changes the teachers were putting on Ender, making it really lopsided and unfair and showing how he managed to overcome it. The first half of the movie was excellently paced, and then it felt like a big rush through the second half. They could have really taken some time to kind of show how Ender was developing as a leader and giving the idea of his progress.
The second complaint I have is pretty much that they more or less give away one of the major plot twits in the book part way through the movie about the ending. Won't say what it is, but it robbed the climax of a lot of its impact. I'm not sure if it was done to not confuse audience members who may not have read the novel, but it certainly didn't have the same jaw dropping effect I had when I hit the same point in the novel.
But overall, a fantastic, amazing movie that makes me relieved that sometimes Hollywood doesn't completely shit upon your childhood and the things that help shape you as a person.