The game takes place in the Vesryn region, which is made primarily of three landmasses: the mainland, the Chrome Circle as well as the Vesryn Spear. The Vesryn Spear is only accessible after beating the Elite 4 and contains the second section of the plot, and then the second region is accessible afterwards. There is a wide variety of locations such as underwater cities, cities in the clouds and even in space.
Journey across the world to help defeat Team Asgard led by Odin (Zeta) or Team Olympus led by Zeus (Omicron) before they abuse the power of certain Pokemon to become gods themselves!
After Team Asgard / Team Olympus finally strikes, it comes down to you to save the world, meeting characters from older games along the way, and avenging what is dearest to you in a story filled with twists. Good luck!
And why not, for a change of pace, visit the Aroma Region? A terrible plague has taken over the region, turning Pokemon into shaded, corrupted versions of themselves. What will happen? Only time- and you- can decide.