http://www.techradar.com/news/super-mario-odyssey-is-the-first-mario-game-to-put-its-characters-at-its-core

When Yoshiaki Koizumi took to Nintendo’s stage at Gamescom earlier this year, he proudly announced that the theme of Super Mario Odyssey was ‘travel’. 

To a certain extent that’s true. The game is made up of a number of different kingdoms, each loosely based on a European country (New Donk City’s New York-inspired setting notwithstanding), which you travel through to collect Power Moons that give your airship enough energy to make it to the next kingdom.