As an astronomy graduate, I can say it's an awesome educational game about physics and astronomy. The history of our understanding of our place in the universe is presented like a detective novel, where you need to use reason and find clues to show that the Earth goes around the Sun. It's the best ways to learn about science.

It took me some extra time to complete the game, because I was looking up things like When did we first measure a stellar parallax, and how precise is our best telescope. And also pictures of Pluto.

The side story from the diary notes is kind of interesting. It does a good job of providing a backdrop to the whole puzzle island.
The music is pretty good.

The game does end in a bit of a cliffhanger, and it doesn't seem like the sequel is coming.