Nadia narrates a complex story about a young girl who is chased by a group of three jewel thieves intent on stealing her cherished pendant. This Blue Water gem, which holds great sentimental significance, quickly becomes the focal point of a global conflict between good and evil. A young mechanic named Jean, who is on a quest to find his estranged father, rescues Nadia from the thieves, and together they become entangled in a struggle against Neo-Atlantis, an organization aiming for world domination. The pair forms an alliance with Captain Nemo (yes, that Captain Nemo) and even joins forces with their former adversaries for the greater good, embarking on adventures around the globe. Those who are new to the series will find the game an excellent introduction to this profound and emotional narrative. Blending elements from Jules Verne with themes addressing the injustices of colonization and oppression, the game places players in the role of Jean, who must leverage his intelligence and mechanical skills to assist Nadia and Nemo in thwarting Neo-Atlantis's ambitions for global control.
In contrast to other role-playing games of its era, Nadia does not incorporate any combat elements. The gameplay is entirely focused on exploration and puzzle-solving, with the narrative taking precedence. The storyline closely mirrors that of the anime, which means that fans of the series are likely to have an advantage in anticipating events. Players can discover a variety of environments, both above and beneath the ocean, and the various items collected by Jean and his companions primarily serve to further the plot and strengthen the bonds among the main characters. There is no character progression, no weapons or equipment to acquire, and no encounters with random monsters for gold or experience points. This complete departure from the fundamental aspects of the genre is intended to enhance the storytelling experience, but it may require some adjustment for RPG fans, particularly those who are not familiar with the series. Additionally, the game does not feature a native save function (excluding save states when played on an emulator); instead, it provides passwords at the conclusion of each chapter.