Comment by sriram_malhar

I think Scratch is fantastic. You get concurrency, timers, reactive programming, multi-media, design elements, and no syntactic rules to learn. So many concepts.

As a next step, I'd suggest GoboScript, that was on HN a few days back. https://news.ycombinator.com/item?id=44026799

This is Scratch with a textual interface, with a few lovely and much needed extras.