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I'm looking for a book (well, an audiobook) that I listened to maybe 7, 8 years ago in English (I live in the U.S.), and for young children, or maybe for teens. My memory is very shaky but here goes:
I remember a boy and his friends entering a competition. I don't remember what the competition was for, but I remember the first stage being some sort of space game or something with each team having a certain target (so sort of like the Assassin game), and the main character eliminated his friends. One of the spaceships had an ability to become invisible, if I remember correctly.
I remember the boy was (intentionally, I think) harpooned by another person competing with him relatively late-stage. The kids/teens were divided into 2 groups and were competing for something, and all had harpoons.
I remember the boy and another boy having to compete by rolling a marble/ball through a maze telekinetically, and the main character barely won by choosing a faster path, despite not being able to roll the marble as fast.
I remember the boy and a girl going into another part of the world that was previously unknown to them (and was sectioned off or something).