Mario is the main character in this fan-dub, and although he normally doesn't speak, he does have dialogue and options provided for him that we be voiced. 

Mario's adventure begins when Princess Peach sends him a letter with a treasure map enclosed. She requests that he join her on vacation in Rogueport and help her find the treasure indicated by the map. When Mario arrives, he finds the princess missing. After meeting Goombella and Professor Frankly, who believe that following the map will lead them to Princess Peach.