I'm sorry, I'm going to have to be "that guy". No, Splatoon 2 is not a new idea. Splatoon was. And Arms is fresh, but I wouldn't include it as a reinvention of anything. You should have just stopped at Zelda and Mario.
Anyways I think a Meta Knight Action game would be pretty cool. One that combines platforming, speed mechanics, and platforming with a cartoony yet victorian gothic aesthetic. Gargoyles.
Also I'm not sure you could call it a "spin off" but we really need a reinvention of Donkey Kong in 3D. A collectathon but maybe some interesting spins on that formula.







