Just from looking at my kids playing, they are really into the same reward aspects as with video games.
1. Recognise ability. Kid loved selfie mode in dialed in. They like daily high scores with pictures.
2. there should be progress, as in moving thru a game telling a story and giving out rewards such as cutscenes, cool comments, music bites, awards added to your char.
On the progress aspect, maybe picking up next game not from the start.
3. Theme matters alot. Some here say, their (young and kids) preferered themes doesnt match our older guys, but i say for example themes such as inception, interstellar, coco, toy story would all be well suited for pinball and please many.
For me personally i think both coco and monsters inc are beyond perfect for pinball, story, sound, visuals, story structure (suited for pinball) etc.