little stuff, things that can relate to the original games but also let's your game more unique
like, in my game you can't but potions, repels, etc, you have to craft them, so the exploration becomes bigger, since you have to look for the items to craft
other unique and little things I saw in fan games, Bushido has katanas instead of HMs, I forgot the name, but there's one with a item that let's you talk with pokémon
these little stuff are so fun and people can be very creative with it ^^