Having thwarted Bowser's previous plot to marry Princess Peach, Mario and Luigi now face a fresh threat in Bowser Jr., who is determined to liberate his father from captivity and restore the family legacy. Alongside companions new and old, the brothers travel across the stars to stop the young heir's crusade.

The adventures of a group of explorers who make use of a newly discovered wormhole to surpass the limitations on human space travel and conquer the vast distances involved in an interstellar voyage.

Having thwarted Bowser's previous plot to marry Princess Peach, Mario and Luigi now face a fresh threat in Bowser Jr., who is determined to liberate his father from captivity and restore the family legacy. Alongside companions new and old, the brothers travel across the stars to stop the young heir's crusade.