So basically 100% without collecting all moons?

It's a good idea but I don't think people will run it very much because coin grinding is very unfun.

A lighter version of this would be All Hats. Also remember you can collect unique moons as well.

I think Frozen_Water_99's idea is good.

FroZen_WaTer_99's Idea is R E A L L Y good old make it (I would do a 100% Costume Run for sure