I've always been a big fan of the Dungeon series in final fantasy. Simple straight to the point RPGs with cute stories and adorable characters.

The Gold Saucer has abunch of cool minigames to play but it would be cool if there was a Chocobo Dungeon game you can make progress on and it can be something you can come back to at the park.

Start the game, make some progress, pause, and go do whatever then come back. It would be amazing to do in between Roulettes.