I would like to add to my above post: NFC features. Obviously, they have to implement anti-cheat rule such as when you're about to fly off, fall off or during Final Smash. As I write this, while I do see the flaws, I still think it'd be an interesting feature to add.
Honestly, though, this would be a better feature for Pokémon. I have more ideas for Pokémon but that's another topic.