Board Thread:Fun and Games/@comment-31609895-20170719163415/@comment-33483162-20171025225937

All the characters in the game refer to the protagonist as "they" or "them" presumably because they don't know either. It's intentionally ambiguous, yeah.

Whether that means it's the character is gender-neutral, gender fluid, or just plain ambiguous is up to you, but there's never any specific clarification either way.