The Mario & Luigi series for me has always been a nice palette cleanser from the more nitty, gritty, stat-heavy RPGs that found their way onto my DS and 3DS. Where many RPGs bank on a player’s appreciation for the minutia of building strong characters and teams, the Mario & Luigi games would rather test the hand-eye coordination you’ve been building up over the various years of playing Mario platformers. There are levels to gain and experience points to earn, but Mario & Luigi, and really all Mario RPGs in general, don’t care about all that. These games just want players to sit back, press the appropriate button at the appropriate time, and enjoy the story. And with Bowser’s Inside Story, there is one hell of a story to enjoy.
Source: Destructoid Review: Mario & Luigi: Bowser’s Inside Story + Bowser Jr.’s Journey