Check out Kodu Game Lab; it was a Microsoft Research project from a number of years ago, and is still maintained. Your son won't need to learn a language, but

Check out Kodu Game Lab; it was a Microsoft Research project from a number of years ago, and is still maintained. Your son won't need to learn a language, but he will learn some of the core concepts from a visual paradigm. https://www.kodugamelab.com/ https://www.kodugamelab.com/