>>49430316Okay I might forget some things since this is off the top of my head but:
SM:
-Story revolves around Lusamine and her story, final battle (before elite 4) is her mother beast version
-Some island challenges are different, but overall kinda easier
-Post game is just some extra area to explore and battle tree. A bit lackluster.
USUM:
-Most people agree the story here is worse. Adds two nobody characters and Necrozma as a final battle instead of Lusamine
-Island challenges are different, most are harder I think
-Post game adds ultra wormholes you can travel through, Rainbow rocket plotline, and keeps the other post game stuff from last gen
-added more Pokémon to the region
-added two minigames. Mantine surf, and photography with your Pokémon.
-added some new ultra beasts and new lycanrock form
