There is a simple game my daughter saw somewhere & later I got it on my phone, she plays it a bunch. I teach a boy the same age as her and I try to find intersections of his interest (We Will Rock You) or else try to get his fingers to learn useful piano feats like a major scale with both hands together, some blues patterns and finding intervals by ear. But sometimes his attention span has left the building. I try to come up with new ways to make it stay then I realized the game my daughter loves might have a similar affect on him and it did. We made a deal, “play the scale 10 times in a row without a mistake and then play the game until you get destroyed 3 times”. This went on quite nicely and it turned the game of piano lesson into exactly that.