What is the climax of this novel? What happens? How do the events of this novel make you feel?

The climax of Ender's Game is when Ender plays the stimulator thinking it was a test, when it was actually was the Third Invasion. What happens here is, Ender invades the buggers and destroys their planet with Little Doctors (a type of weapon). Ender didn't know it was a test and sacrificed battleships. Not knowing this in the beginning he got angry because he led people to their deaths.

The events of the novel gave me the feeling of sadness, happiness, and anger. I felt sad because Ender was just a child when he went to Battle school. He was separated from his family, especially Valentine (his sister). Ender's life is also sad. He cannot return back to earth after he went to Eros. He can’t return to his family. He had to kill other people around his age to survive. The teachers put him into a position that was dangerous. The teachers made him an enemy from others. Another thing that makes me sad was that Ender is not free. He has to do everything he was told to do. I feel happy because I am not like Ender. I am not living in his world. I don't need to go through the life he has been through. I live a happy life. I felt myself getting angry as I read this book because they treated Ender badly. They weren't nice to him one bit. He wasn't treated like any other child. They made him a killing machine. His parents also sent him to battle school when he was seven. He couldn't have a life like other ordinary kids. Another reason I felt angry was because he was tricked all the time. The administrators of the battle school used Valentine to convince Ender. They use Ender's family to weaken him.