Rite so here is my idea (if yous havent already done it) maybe throughout the game there should be interactions, sightings and even quests recieved from some of the characters from the classic pokemon series (and even some newer ones), for example this new region yous are developing is still mostly unexplored and has many hidden secrets, what if maybe you interact with prof.Oak as he studies this new place, maybe get a quest or 2 from him, Brock could have set up a breeding center and misty could be seen giving tips on water type pokemon, and so on.
I think implementing these characters for however small a part could make it fun and mildly familiar but not so much so as to kill the uniqueness of it, you know, what do yous think?