The similarities are how his brother (peter) is mean to him and in the movie peter, acts the same in the book and in the movie. In the movie and in the book the adults lied and manipulated ender to kill all of the buggers for them. In both movie and book ender's sister really cares for him and loves him very much and they both trust each other.
There are similarities, but there are also more differences. Ender starts the program at 6 years old, but in the movie he starts somewhere around 12 years old. In the book Ender