Blue Submarine No. 6 is a post-apocalyptic naval adventure game based on the classic manga and its anime adaptations. Players lead an undersea salvage crew in this game, interacting with other players using menu-driven exploration and dialogue in its adventure mode.
In the game's first-person 3D simulation, players must salvage parts from crashed ships and other finds on the ocean floor when they step into their sub. The adventure mode features a mix of 2D backgrounds with highly detailed polygonal characters, while key story scenes are told in animated cutscenes provided by Gonzo.