This is probably one of the most sophisticated and profound picture books I've seen in a while. Not only is the stylized artwork unusual in the best sense, but the story in this sci-fi picture book asks some of the hard questions that you don't often find in a picture book. Questions like "What's the point of being alive?" and "What's at the end of everything?"
Ostensibly about an astronaut on a mission who lands on a strange planet populated with incredible creatures, where even some of the landscapes appear to have arms and legs, this book is about so much more, including how friendships endure through memory, even when our friends are gone. Many of the book's themes are encapsulated in some of the quotes that are on the last page of printed matter. There are quotes from J.M. Barrie's "Peter Pan," Stanislaw Lem's sci-fi masterpiece "Solaris," Emily Dickinson, Philip K. Dick, Carl Sagan and more. Make sure and read them. I think they will give you a greater understanding of this amazing book.
Without giving away any spoilers, I will say the ending of this book is mystifying. After reading it the first time, I immediately went back and read the whole book again, searching for clues for what the ending meant. I am almost positive that every reader will probably have a different interpretation for what happens at the end. If you get nothing else out of this book, it will definitely start some interesting conversations and for me, that's a sign of a great picture book.