Interesting. Is it best of all Fanmade games or you think there are better ones?
To be honest I have tried just that and another one similair, I think it was inspired by reborn, which was worse. But imo it is better even than the original ones in many aspects. I mean the official ones are good, the graphics get better with each release, but as long as story, content, puzzles, battles go this one is better but maybe it is just my taste.
Something that I like but maybe not everyone likes is the more "mature" content, I mean I grew up with pkmn since mid school but as I grow up they stayed the same and kept targeting the same audiance, children, maybe they changed that a bit with their last film (detective pikachu) but that is all. We here have a story more real, out of the candyland which pkmn world is and always will be. Here people kill pkmn, pkmn kill people, the pkmn region is rotten to the core lol, the devs had no problems trowing any kind of curve balls. 2 important characters battle and then the one who wins order his pkmn to decapitate the girl, 2 female gym leaders are implied to be in a relationship and many others (even suicides). It is something I like because the story feels real and out of the pkmn candyland (then maybe for somebody this could be a bit too much out fron the usual pkmn world).
Another thing I like is the difficulty, it is way harder than every official pkmn game but they worked a lot on that. I will just say there are allbthe 807 pkmns that were released until 1 or 2 gens ago (don't know), they picked out the strongest ones you find in online tournaments and made them way harder to get, usually after complicated puzzles you can get just 1 of them (pseudo legendaries mainly so from dratini-dragonite onwards so metagross, salamance etc.)
Then there are the field effects but I have already gone too mich off topic XD