>>54601379>Black and WhiteBetter mon distribution at the start of the game (first 2 gyms).
Improve Gym Leaders by giving them more than three pokémon max, and making some of them use the new battle formats. (first gym leader challenges you in a triple/rotation battle depending on the version)
Implement the Dreamworld in game, so to not make it unavailable after the end of service.
Keep the cities added in B2W2 for postgame, and keep the new gym leaders as post-game bosses.
Other than that i don't really know
