Orson Scott Card said he wrote it for a youth audience. genre: teen my friend.
BTW: I have to ask, you consider The Hobbit a kids book but won't place Enders Game in the same category?
ADDENDUM: I might be misremembering my author sides. Card may have written the short story for a more mature audience and the subsequent novel was expanded and adopted for youth, whereas Tolkien wrote the Hobbit for youth (I think his nephew had a lot of critical input) but was adopted by a more mature audience...
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