I’m not sure about anyone else here, but I am personally interested in seeing the process of how things are made on The Hive (art wise).
Now that Hive merchandise is coming soon, I think this will be a great time consider a book that includes concept art work for past costumes, avatars, game unlocks & more.
Seeing concept art for other things like Mailbot, game mode maps or even the hub itself would be super interesting to look at as well. If The Hive still has concept art work for the Sonic hub that would also be fun to look at as a Sonic & Hive fan.
Maybe the book could provide the readers with concept art of a few unreleased store costumes or even pets that are coming soon.
I myself have tons of books that show off concept art work for games like Overwatch, World of Warcraft & Diablo. These types of books are very popular and are sold well.