The thing is though, how often can you say you knew it was a spoiler until you've actually seen the movie? Just cause some scenes from the beginning, middle, and end of the movie doesn't mean the entire movie was completely spoiled for you.
Gregory McMillan said:
I don't usually complain.... But, Ender's Game. What. The. Hell.. The first couple lines is the big reveal near the end of the novel
From the get go the movie was never going to keep the big reveal (and seriously if you didn't read the book you still might not have gotten it from the trailer), but instead rely on the drama created from the audience knowing what Ender didn't.