I know most won't care, but some sort of "recorder" that can play the one-time music themes of things like legendary encounters, special NPC trainers, etc. as well as the ability to remix the themes as well, just for fun. Maybe make that a puzzle you have to solve to get into a gym or something? I don't know. Also, I want that mixer thing from DPPt back, where you can slow down the cries of Pokemon. It was small but fun. On that note, I also want them to keep that weight and height scale from BW and B2W2 as well. I like seeing the real size of the Pokemon, but also add in the ability to change your character's height and weight as well, for accuracy.