For a gainfully employed plumber, Mario sure has a way of job hopping. From being a mega movie star, to being a multifaceted sports aficionado, to being an Olympian, to being a kart racer, to being a fighter, to being a toy collector, Mr. Super Mario has worn a number of radically different hats since debuting in the seminal 1981 arcade game “Donkey Kong.” And yet, in this writer’s humble opinion, Mario has been at his best when he has abandoned the fancy trappings mentioned above and just goes for a flat — literally — look. Paper Mario is a version of Mario that is as he sounds: He’s a flat…