>>37996353I had a similar idea when working on a fangame.
I was making the friendship calculation much more integral to play. Man-made healing items were very expensive (there was a shortage, part of the lore) and so bitter herbs and berries were the staples. Friendship affects accuracy and other in-game events, such as tms and item gifts. The world is has many events that increase/decrease happiness, meaning exploring towns and routes feel more impactful. There are more food shops, spas, and a carnival. I based lots of events off of often unused identifiers, like egg type and color, to really encourage catching them all.
There would be feral Pokémon in the wild (I never got this far in making it). These have high IV and great attacks/abilities, but extremely low base friendship when caught. Some event ones are uncatchable.
Secondly, with less readily available items, more exploration is key. No HMs, but optional branches, with actual puzzles. Speaking to NPCs helped you solve the puzzles, so there was more reason to talk to them, without it being a requirement.
I also made eviobrite and eviomite, to boost special attack and attack respectively, and was often held by trainer Pokémon, so nfe were sometimes more powerful than perceived. I wanted this to be like the stadium games, were there was an actual reason to use nfe.