Play is more a search for novel ideas by practice.

Discovery of new ideas, and absorbing. Different types of learning.

This is part of it, a lot of play is taking ideas that have already been around and allowing yourself to come to a personal understanding of them. In sports this could be biomechanics, in math this could be an understanding of a complex theorem. I guess in a sense ideas can still be considered novel to each person until that person gains understanding.