The Mario & Luigi RPG series started on the Game Boy Advance, and even many years and a few iterations later, it has always reflected a connection to those roots. The two-button Game Boy Advance was the impetus for the series’ central hook: Each brother is assigned to a face button and you control them both at once. Even as the series has progressed to platforms with more face buttons, the core concept has remained defined by its initial limitations. Now brought to the Switch, Mario & Luigi: Brothership feels like a conscious effort to escape those limitations, resulting in a lengthy RPG that can’t quite sustain its own weight.

In Brothership, several denizens of the Mushroom Kingdom are magically swept into the new setting of Concordia–a vast sea dott…