Plot: Tweens are recruited into the military by Col. Graff (Harrison Ford) to battle an alien invasion because of tween's superior strategic skills, and Ender Wiggin (Asa Butterfield) is one of these. Ender is bullied by all the other cadets, but he keeps getting promoted because he is the best. Along the way, he becomes platonic friends with Petra (Haliee Steinfeld.) Soon he finds himself in deep space getting ready to battle real alien ant-people. [imdb] [photos]
A second gap is the Asa Butterfeld's Ender isn't that sympathetic. While the lines are delivered well enough, he was like a cerebral superhero -- too distant from real world experiences to evoke emotion. When he threatens to quit, it feels like an intellectual power game; part of the mental "chess game" he is playing with Ford's Col. Graff. It doesn't feel like he needs to be with his sister as he claims.
Harrison Ford provides some good dialog and facial acting, but it is in service a bullying plot line that is predictable.
Speaking of bullying: Ender usually he beats up the bully using superior tactics, but the point is to use violence to fix violence. This aspect of the message makes the story feel much older -- like WWII era Sci-Fi stories. I was surprised that the novel was written as late as 1992, because Star Trek Next Generation (from the same period) was far more progressive. Maybe author's Orson Scott Card's conservative views extend beyond his views on homosexuality.
The special effects are great. There are good action scenes in the weightless sports-game that seems to be a cross between Quidditch and football. These are probably the best scenes in the movie, but they are less interesting and suspenseful than Quidditch in Harry Potter.
I liked the ethical dilemma posed by the end of the movie. This began to redeem the movie, but it was pretty campy. I am glad they felt bad about what they did after it was all done.