Looks like another educational approach to a language that isn't really
meant for kids. But the approach is not meant for productive use either.
So I wonder, what should be the target audience. I can't see one.
If I were forced to use blockly in conjunction with logic design, I'd
rather put the focus on abstraction and debugging. With this current
approach, it seems you can point/click language elements, but that
framework is of no use from a designer point of view. And if I were a
kid, I'd a priori want to see what my language construct is doing, not
getting confused by language elements.
I gave the thing a go, and just managed in under a minute to create an
illegal construct. Maybe the author should revisit the idea to match the
educational block approach with a non-intuitive, heavily complex
programming language.