>>31706995Gold/Silver 2
All johtomons are available before postgame. Fuck Houndour not actually being available until Kanto.
New evil team is Team Augur. They want to power a giant drill and dig a tunnel under Mt. Silver (which is shitload larger now) and all the other caves where they can take away all the Gold and Silver Ore form under there, even though removing it will destroy the mountain and split the continent into pieces, potentially killing everyone. It's called Gold/Silver 2 because actual Gold and Silver minerals are important to the plot.
A few new pokemon include several drill-based ground types that the evil team can use, invasive Stink-Bug species that is Bug/Dark with a lot of Poison type moves, and a new pikaclone that is Electric/Poison pokemon that is considered a pest and grew immune to the poisons meant to exterminate it.
Mega Lugia and Mega Ho-Oh are the box legends but they play zero importance in the story, catching them is an optional sidequest for after you get the 8th badge (you can use them to destroy the elite 4)
Region in general is a bit dirtier and more polluted, kinda like Rust Belt America or Eastern Europe, like it was once thriving, a lot of the businesses moved out, and the fringes are going back to nature, albeit slowly. More poison type pokemon, a few more bugs and dark types too.
Gyms are totally different, none of the old leaders return, except for Karen, who's still in the Elite 4 but she's old now, and Falkner, who is the Champion and successor of Lance as the Flying type Master. Ethan can be battled in post-game, but he has, like 9 different teams all chosen at random whenever you fight him. Elite 4 is moved to Cianwood's island, which is much larger now because of piers and docks.
Garbage Island is a new place. It's a literal island made of garbage in the southern seas. You can ride a trash barge out there from Cherrygrove early game to go catch stuff like Grimer and Trubbish.