I think the projects are larger - or at least move from small ones like quines:

https://en.wikipedia.org/wiki/Quine_(computing)

)

to large ones writing simple compilers.

Good (accurate) review at:

http://www.computinghistory.org.uk/det/12325/Etudes-for-Prog...

and interviews with the author:

https://demin.ws/blog/english/2012/08/25/interview-with-char...

https://sudonull.com/post/27422-Breakfast-report-with-Charle...