Mario Sunshine was first revealed to the public at Space World 2001 (an annual showcase of the hottest Nintendo games held every year in Japan). Fittingly, Mario Sunshine was showcased in video format by Shigeru Miyamoto -- the internationally revered creator of Mario, Zelda, Donkey Kong and many more of the industry's most well-established icons.
This video showed Mario in action, exploring a huge environment filled with trees, water, buildings and of course plenty of sunshine. Mario was seen wall-kicking and running from enemies, but we're just now beginning to learn about the plumber's new abilities. Most notably, Mario is carrying a cool water-toting device on his back, presumably used to launch water at enemies.