After having saved the Mushroom Kingdom for the nth time, the bros were contacted by Professor E.Gadd to assist him in a scientific expedition to the old and abandoned Mushroom Kingdom (now called Mushroom Falls).
They’re helped by Vivian the Shadow Siren who wears a strange magic amulet, and Toad the brave driver of the EGadd Machine: their headquarters.
Together, they’ll go on their greatest adventure yet!
Mushroom Falls is a place full of secrets and danger. It hides the clue to a mysterious question written in a journal they found there: is all of their adventure just a play?