Simplier gameplay and a lot more characters. Have a mode where you can choose 3 battle pokemon and then 3 assists to choose from so you have a full 6 pokemon team. Also a hub world for your trainer they need to go big with the player character aspect since the core fanbase playes rpgs. They could make it as great as they'd like desu. Pokemon has the money. Sadly they wouldn't dare make a spin-off that could potentially outshine a main series game.