Deep Fighter, released in 2000 for the Sega Dreamcast, is an underwater shooting simulation game. Players take command of a variety of submarines and engage in various missions that blend combat, strategy, and resource management. Set in an expansive undersea world, players must defend their home against invaders, navigate through treacherous waters, and upgrade their subs to withstand the dangers of the deep. The game combines elements of action with complex missions, appealing to both casual players and those seeking a deeper gameplay experience.