Pokémon Super Mystery Dungeon builds upon the previous Pokémon Mystery Dungeon games and gives you more than one area to explore. In this game, there are multiple continents to visit, each with stores in, access to different dungeons and more. Each conintent also may have multiple locations to explore outside of dungeons. They can be accessed by purchasing Passports from Kecleon and then riding Lapras to the continent.
The continents don't change much between them, but they do give access to their own set of dungeons and feature a variety of different Pokémon to talk to and connect with.