Kudos to the writer of this book. You did an amazing job. Why don't you try to publish your book in NovelStar? A lot of readers will love your work, judging from the book I just read.

I think you do a great job showing the relationship between Josh and Kora. Rather than telling us how close they are as siblings you show it with their activities on the beach and lighthearted dialogue. I don’t know why I never made this connection before but Kora reminds me of Gammorah from Guardians of the Galaxy with the green skin. Don’t know if it’s intentional on your part but kudos if it is!

Kora’s dialogue also worked good because of of the stilted, almost too literal style of her voice. It meshes well with the more human voice of Josh and reminds us that she is not of this world.

I liked the brother sister relationship here. Even though Kora is an alien, they had a regular sibling relationship and it felt natural. I also liked the thought you have put into the alien species and world, and dropping hints about the new species coming in.

I like how you tried to build intrigue with Kora's description as a green skinned girl. If you had introduced her earlier, it would draw the reader in sooner. We want to know why she is green skinned.