I thoroughly enjoyed the movie version of Ender's Game, but agree wholeheartedly with the reviewer's take on what succeeded and what failed. In fact, I probably enjoyed it so much because I expected much less. The glaring failures were all necessary to make a successful movie, but they still managed to indicate the most important philosophical points. Yes, Graff was harder than in the book (and Anderson's softness was used to make up for this), Bean was introduced too early and wasn't adversarial at first like he should have been, and what were they thinking with the romantic overtones with Petra... But we know why Ender did what he did and how it affected him, and that didn't change from the book.
My one sadness about this movie is that it didn't inspire my son to read the book (he started it last year, read the first paragraph of Graff's pre-chapter conversation, and decided he didn't want to read it). But at least my copy is now on loan to one of his friends who was inspired to read it.