I really think the best thing for teaching kids would be giving them a fully built 2D game and teach them how to mod it, slowly working into how the core engine

I really think the best thing for teaching kids would be giving them a fully built 2D game and teach them how to mod it, slowly working into how the core engine works. Not that I have any real evidence to support this. But my casual involvement in Half-Life/WC3 modding scenes during my teens says this is the way to go.