https://www.polygon.com/2017/10/31/16576820/super-mario-odyssey-secrets-easter-eggs-new-donk-city

Super Mario Odyssey is like a cluster of tiny, beautiful toy boxes collected into one package. That’s abundantly clear when you hit one of its most memorable moments: the finale to everyone’s favorite kingdom, New Donk City, where the game delves back into Mario’s beginnings for some brilliant, nostalgic level design.

Spoilers for the Super Mario Odyssey campaign follow, should you not have finished the Metro Kingdom yet.