>>34322525Crystal was literally the same game, with "sprite animations", graphical update, the novelty of being able to choose a female trainer (which is why many people bought it, and I'm serious) and the Suicune quest. It also added the Battle Tower and, in Japan, wireless trade through Internet.
It wasn't very much, but at the time it was nice.
Emerald was a fucking revolution. Sapphire and Ruby were subpar games, which let down many many people. Having a different enemy Team depending on the version was original but was horribly handled, and their goals were retarded. Emerald fixed this, fixing the story and making them battle for awakening their legendary and you being in the middle. It also added a lot of things, fixed many problems and introduced the fucking Battle Frontier, which, in a time when you couldn't play online, meant A LOT of hours playing Pokémon.
Diamond and Pearl were OK, but regional Dex was shitty and the game was slow. Also, the story was more or less the same as RS. Platinum fixed the regional dex, fixed some of the speed problems, fixed the story, and again added a Battle Frontier. Also, made the game more challenging.
Black and White were perfectly fine as they were, so they opted for sequels, and it was handled very very well. Added PWT, which is a thing that should be revisited, and more in gen 7 as it was supposed to be a celebration of the 20th Anniversaire.
XY were shit, and luckily Z never happened. Best decision made by GF ever.
SM were very good games, but lacked freedom and a real postgame, and had the fucking festival plaza nobody liked. Everybody expected USUM addressed these issues but no. They CHANGED things that were perfectly fine in the originals just for the sake of change, making things even worse (story). They didn't fix the main problems in SM, and only added little things that, while they are pretty nice, don't justify a full release price.