I don't have a specific feature in mind, but what I would like to change is: Features that requires time, instead of skill. I think the games have been focused on taking too much time for the players, rather than skill. Personally, I'd like a harder walkthrough and less time consumming tasks.
This is a good idea I think.
I am not thinking about everything else, except for the return of the seasons and the customization of our character.
I've seen some trucks in the designs, we might be traveling to other region. But at the same time, I don't see why they'll do that because we have Fly...
Oh!! talking about HM... Items! instead of Hm...