A systemic sidebar.
Aside from the Warrior-Jumper’s startling ability, there are other mechanisms of note. The “movement” system was especially interesting, I thought: characters have a certain number of Movement Dice, and the values these things turn up become a currency you can spend, with each class having its own peculiar economy. I say yes to that.
If you think of “hit points” and “elfs” or whatever as the lines, the thick black ones which constrain the set, he’s coloring them in with aplomb. As his pretend uncle, I could not be more proud, even if he is at the age now where adults being proud of him is cause for embarrassment.
I mean, look at this stuff:
Logo samples he made with his consultant/playtester/babysitter.
Looks like he already understands the DM’s true alignment.
“Jungleafy”? What? How could I love you more?!?