All the elements gel perfectly here: The characters, the combat, the game flow, the dialogue. More than that, this is a game that revels in simply being a game. It celebrates the best parts of both role-playing and Mario games while mercilessly lampooning their worst habits. It's absolutely brimming with exuberance.
And with disgustingness, too, of course. But somehow, when it's Bowser's guts you're wallowing in, even that doesn't seem like such a bad thing.