that looks cool to me, thanks for sharing. I think something that works well for kids is instant feedback on their code/tweaks, looks like this has it.

PICO-8 sits in an interesting spot where it's not exactly a "toy" language/environment the way Scratch is, nor is it especially geared at learning, but on the other side of things it is based on a real programming language (lua) and there's an interesting scene for it where people flex pushing it to its limits making demos, demakes, etc, many of which are far beyond the NES-level capabilities it's meant to have.