It's the marquee title meant to show off the capabilities of the Nintendo Switch and redefine the classic series for an an entirely new era, which is no small feat considering how many times Nintendo has had to do that over the course of three decades.
Super Mario Odyssey marks the first 3D Mario game since Super Mario 3D World in 2011, and arguably the most important Super Mario game since Nintendo used Super Mario 64 to bust the plumber into 3D and launch the N64 way back in 1996. A simpler explanation might come a little closer, or at least make more sense to more people. There oftentimes feels like there's no great way to describe Mario: sure, we could call Super Mario Odyssey a collection-based 3D platformer, but something about that comes dreadfully short when trying to capture the spirit of a body-hopping hallucinatory ride through a series of increasingly strange kingdoms populated by sentient utensils and top-hatted rabbits.