スチールダイバー (Steel Diver) is a Japan-exclusive submarine simulation game developed and published by Nintendo for the Nintendo 3DS handheld game console. The game is set in a deep sea environment, with the player taking control of a submarine and navigating through treacherous waters while engaging in various missions and battles. The game features a variety of submarines to choose from, each with its own unique characteristics and abilities. The game also includes a variety of missions, such as rescuing survivors, engaging in battles with enemy submarines, and exploring sunken ruins. Additionally, the game features a variety of mini-games, such as fishing and treasure hunting. Steel Diver also includes an online multiplayer mode, allowing players to compete against each other in battles and missions. Steel Diver is a fun and immersive submarine simulation game that offers a unique and challenging experience for 3DS owners.