Hello. There will be a artbook that also includes the game's lore.
The book will contain, aside of all art assets of the game, more detail on the world building, early designs, art WIPs/progresses as well as developer commentary and behind the scenes discussion.
Although only the supporter exclusive version for the ones who backed us on our Kickstarter campaign or pre-ordered the book here will get access to any deleted scenes / extra scenes that didn't make it into the game.
We hope that answers your question, thank you for your support.