I think anything can be made into a game, really. the only thing that limits us is our imagination!
I remember when I was a kid, I grew up with the Jumpstart series. it was basically a game composed of a bunch of minigames that taught stuff like how to do simple math, understanding change (vending machine minigame) and just a bunch of random stuff. it was super fun, really.
I still think these things can be fun in games at times, because it will usually catch me off guard lol. stuff like a riddle or a sudden simple addition question makes me like oh shoot! I really need to think about this! xD
in all honesty, I believe there is an audience out there for anything you can create, so just let your imagination guide you!