Yooka-Laylee's worlds are contained in books, which can be expanded with pages

Coming from studio head Gavin Price...

"This time around, the worlds will all be contained within these larger magical books and we'll have quite book-ish names for the levels as well. Sometimes they'll sound more like titles of books when you go into the levels and you'll explore them that way by collecting Pages as well. So you can go into a world, and it'll start off similar to a Banjo level in terms of scope, size and complexity, but then you can spend your Pages expanding the current world or use them to unlock a future world as well."