I've seen a few things from Liukas, and shared her Principles of Play video on Hubski before.
I really enjoy Ruby as a programming language, and there's some really high quality resources out there for it, but few target teaching it to children and in schools. Liukas' book provides fantastic hand-drawn activities that she has tried and tested with Ruby Girls, a franchise of local groups to get girls interested in STEM that Liukas co-founded.
My hope is that most of these can be applied in a classroom, providing that all important variation in learning (and play) styles.