Blue Shark is a shooting gallery style game with an underwater motif. Upon starting a credit the player has 99 seconds to spear as many aquatic animals with their spear gun (modeled on the cabinet) as possible. Points are awarded based on the difficulty of the target: the Octopus is worth 400 points, the Swordfish 200 points, and the shark is worth 300 points in the foreground or 500 points in the background. Starting at 60 seconds remaining a skindiver will begin appearing, and will subtract 500 points if hit. If the player can reach 18,000 points they will be rewarded with a free game.

By using a blacklight, interior cabinet decorations, and a see-through reflective mirror surface the game cabinet gives the appearance of the game figures floating in underwater 3d space.