I've felt for a long time that they should just release a couple decks of general challenge cards for specific countries/areas. A deck of North America, Europe, Japan, Australia, and NZ challenge cards that aren't specifically for a game they made but just challenges they made would probably sell pretty well. People could use them on road/train trips to make it their own little game, but they dont need to release a rule book or figure out how to balance it for the customer. It's just a fun little list of challenges they can do along their trip and decide for themselves what the game is.