I want more spinoffs. Captain Toad is a must for me. Other spinoffs that were enjoyable were Diddy Kong racing, and Luigi's Mansion.
I want a Sim City style game where you use Toads to build your own Mushroom Kingdom from scratch. You'll have different classes of Toads. A game like this would be perfect for the gamepad. There will be builder Toads, Farmer Toads, and Guard Toads who protect the kingdom. Your goal is to build a kingdom from scratch while fending off attacks from goombas, koopas, and the like. Online coop would be a possibility with various modes from racing to build kingdoms, to defending the kingdom from a horde of enemies.