This is great! A few years ago, I did something similar for my son and 3 of the neighbor kids. It was a very minimalized D&D type of game where they each picked from a stack of predefined player charts, then played a simple but thrilling campaign to rescue the kidnapped king. There were a few routes they could take, each with different hints and warnings from villagers along the way. In the end, 4 boys from ages 4-7 sat at the table, engrossed and attentive, for over 3 hours. They've since made their own maps and stories, though I think the making has been more fun for them than actually playing.

I love this approach, though, as it is almost something a kid could play by themselves or more easily create for one another and play together. It could even be played in the car on trips, reducing whining about playing with the ipad. (I didn't have ipads when I was your age!!)