I remember reading a book about game design (can't remember the title) that viewed game design through the concept of 'lenses'. One of the lenses was "first make a toy, then make a game around it". For example, a ball is a toy, and football, basketball and volleyball are games.
Yeah the book is The Art of Game Design: A Book of Lenses by Jesse Schell. It seems likely this principle was inspired by the book, the author recommends it on a different page.
It’s a good book which would also be great as a set of prompt cards IDEO style.
Edit: On a whim I googled and it does exist as a card deck as well!
