Twenty Thousand Leagues Under the Sea

Fushigi no Umi no Nadia, known as Nadia: The Secret of Blue Water, is an action/adventure game for Sega Mega Drive developed and published by Namco. Released on March 19, 1991, in Japan only, it is a faithful adaptation of the NHK anime series based on Jules Verne's novel. Players control Jean, a young Parisian inventor, and Nadia, the mysterious girl with a blue sapphire, as they embark on a global adventure involving submarines, airships, and ancient civilizations. Gameplay consists of a top-down point-and-click adventure where players explore labyrinthine environments, solve puzzles through interaction with NPCs and items, talk to characters, collect items, and progress via chapter passwords. There is no combat. The story follows Jean and Nadia uncovering the secret of Blue Water amid Atlantean conflicts, with deep character backstories and emotional payoffs. What makes it stand out is its dense, anime-like narrative full of heart, tragedy, and over-the-top twists, despite tedious backtracking and maze navigation.