Play Fushigi no Umi no Nadia (english translation) Online

Fushigi no Umi no Nadia came out for the Sega Genesis in 1991, developed by Gainax. It's an action platformer based on the anime, and it fits right in with the kind of licensed games you'd see on the system back then, with colorful sprites and straightforward level design.

You control either Nadia or Jean, switching between them to use their unique abilities. Nadia can throw her pendant as a weapon, while Jean uses a slingshot. The goal is to navigate through side scrolling stages, avoiding enemies and solving simple environmental puzzles, like moving blocks to reach higher platforms. Some sections even have underwater sequences where you need to manage your air supply. The game moves at a steady pace, but it can get tricky with enemy placement and some precise jumps. It feels like a direct, hands on trip through the show's world.