I started all this by saying PPLs were surprisingly visual and physical, so I'm concentrating on the interaction loop that I had in mind when I said those things: every time you edit a program, you see how it affects the distributions of data flowing through.
So in the attached GIF, there's a dataflow graph for a simple model where every few seconds I add an additional wire.
PPLs don't solve for a result—they converge. So I expected the visualizations to have a very springy response to changes. And that's what I get! In fact, the juiciness of the program output contrasts so much with the stilted UI that I might have to resubscribe to some game design blogs sooner than later. 😬
But this is good. I have ideas for where to take the language that are milquetoast but implementable by me in my spare time, at a pace that I think should allow me to explore complex models within my lifetime.