This is wonderful for folks who can understand concepts presented to them visually. If I had access to this as a child, I could have definitely grokked function

This is wonderful for folks who can understand concepts presented to them visually. If I had access to this as a child, I could have definitely grokked functional programming faster :) I can only think of one major improvement - add the concept of synchronicity/asynchronousness. Perhaps a visualization to illustrate difference in function completion times or race conditions will help!