The other day I refused to fire it up for him and he had a full meltdown. I told my wife I had never seen product market fit like that before.
It is a little harder with something like a game to maintain motivation and go for perfection when you know your audience is an audience of one but it’s also a relief to just worry about the things he cares about (trains and firetrucks).
I also miss there being something intellectually challenging to a side project but that probably means I just need to learn a real game engine after this.