Agree 100%. Since dad helped, I was expecting to see sprites sheets, or some JS classes for some OOP, etc. Was pleasantly surprised to see how "simple" the approach was for such fun output with a decent amount of variety.
He doesn't understand what a sprite is, or really the motivation behind sprite sheets. To him they're just animated images he made in a tool. Internally he switches the "costumes" of characters (terminology he got from Scratch I believe).