I've played quite a few times, got the nugget man mission, but not the secret mission. I haven't been playing every day though, I wonder if that affects it.
If anyone needs a free US code, just go to this website www. ytv . com/blog/get-a-special-demo-version-code-today
Remove the spaces and get your free code.
Anyway, I keep on seeing this huge empty green island during the flying cutscenes in the demo. Hopefully that's where the Battle Frontier will be. Probably going to revealed in a few days in the next CoroCoro if it is but I can't help but be excited for it. The Hoenn Battle Frontier was one of the best things ever.