Mario has been many things over the years, but this, I'm sure, is a first. Bowser's Fury, the generously sized standalone expansion included in the Switch re-release of Super Mario 3D World, is Mario as a very modern open world game; a sandbox with the edges slowly being pushed back to reveal the map in its entirety, where there are towers to climb, secrets to unearth and even what amounts to a day/night cycle with bad weather rolling in to herald the coming of dark. This is Nintendo taking Mario somewhere it's never really been before, and the results - while a little lumpy in places - are never anything less than fascinating.
If an addendum to any entry in the series would be so bold it makes sense that it would be to Super Mario 3D World, the Wii U original that saw the Tokyo EAD team at its maximalist best in its desire to throw absolutely everything in. This is the Mario game whose levels pull in from everywhere and anywhere, from full-on tributes to Mario Kart and The Legend of Zelda to the more obscure parts of Super Mario's own past. Just as Super Mario Bros. 3 seemed to inform the spirit of 3D World's predecessor Super Mario 3D Land, it's Super Mario Bros. 2, of all things, that seems to set the tone here.
It's a more kinetic brand of action, in short. Like 3D Land before it, 3D World mashes together the traditions of 2D and 3D Mario - levels are a race to the flag, while Mario's movement is more digital, with moves like the triple jump excised entirely - but the big new trick here is four-player co-op that's supported throughout. It's a lift from the New Super Mario Bros. - and you can't help but feel an attempt to push the 3D Mario series towards those same levels of sales - that introduces an electrifying level of chaos to it all.