https://www.gamespot.com/articles/every-kingdom-in-super-mario-odyssey-spoilers/1100-6454444/

Super Mario Odyssey is technically an open-world game, but it's actually split into over a dozen open environments--17, to be exact. These range from the festive Sand Kingdom, which features a mix of motifs inspired by ancient Egyptian architecture and Mexico's Day of the Dead holiday, to the vibrant, hunger-inspiring Luncheon Kingdom. Every location has character of its own and a surprising number of puzzles, platforming challenges, and hidden secrets within.