If it's optional and doesn't cost me anything that others are able to buy themselves some silly game to play while they play Elite, then I don't mind, but...
As optional thing, it shouldn't have any connection to main game (and most likely wouldn't). You would just play your Pokemon or whatever instead of playing Elite, which would be a waste of effort on devs part, because people who want to play some other game do simply that.
As far as minigames go, it could be fun idea to add some game of dice or something like that to Odyssey. Players could play for money and it could work, just like it does in other games.
