Terra Diver is a vertical-scrolling shooter. The player picks one of three different ships - red, green or blue - each with their own pilot, fire pattern and laser web. Each ship has a standard gun and a bomb, but the most distinctive of these aspects is the laser-web: holding down the button for the standard gun will release a lock-on laser-web traditionally shaped as a cone or semicircle, which will destroy the enemies it locks onto after releasing the buttons. Each ship has two different lock-on weapons that function as web-designed laser targets. Once an enemy enters the web's range, the player can destroy the enemy or multiple enemies can be destroyed via homing lasers or multiple fire-balls. The game is unusual in that, rather than using a 3:4 aspect ratio to better suit the vertically-oriented gameplay, it uses a horizontal monitor (4:3) in the style of Neo Geo vertical shooters as well as the later Radiant Silvergun and Giga Wing.