Downloaded it... started playing with it... and it's actually pretty cool. You can make games, interactive animations, all sorts of things. And it's actually pretty simple... yet provides a great background on event-driven (and also both functional and object oriented) programming, including variables, logic elements, etc. Even I, having been programming for for nearly a quarter of a century, enjoyed it.
That being said, here is the initial version of my 12-year-old's "Easiest Game on Earth" (his moniker when I mentioned that it didn't have any way to lose). A little input from me, but he did a lot of it himself. Not bad for a first attempt! Enjoy...