This is an exploration novel. There are many interpretations of unsolved mysteries in the novel, such as the mystery of human evolution, the origin of the moon, whether myths are true, the mystery of ancient humans, etc.
This is a suspense novel, and the mystery is laid out from the first chapter of the novel.
This is another science fiction novel, because all the arguments can be supported by actual theory. Although it is a bit advanced, it is by no means a YY work.
Our story begins on a small island...