Champion caps at Level 50 (60 rematch)

Gym leaders have more diverse teams; i.e Sabrina not just using the Abra line

Eevee gets a Light Ball Equivalent.

The Eevee In Celadon is a Pikachu in the Eevee Version.

Team Rocket and Mewtwo play a bigger role.

Trainers have been added along with small location changes

The Safari Zone contains Alolan Forms in the Post Game

The SS Anne can be reboarded in the Post Game.

The Truck is in the games and has no Mew but it does have a Big Nugget.

The only post-game is a Battle Tower-like facility.