Bermuda Triangle is a side-scrolling action game for one or two players. You are the pilot of a mini-sub exploring the waters in the Bermuda Triangle. Your goal is to earn as many points as possible by collecting treasures and destroying various enemies you'll encounter. Your mini-sub is equipped with a tractor beam which can be used to collect treasures found along the bottom of the ocean; when you successfully retrieve a treasure, you will then need to carry it safely up to the research vessel on the surface. Your mini-sub is also equipped with lasers which can be used to destroy the many dangers you'll encounter, including giant squids, man-eating sharks, mines, bombs, enemy ships, and more.
The gameplay involves navigating your mini-sub through the ocean, avoiding obstacles and enemies while collecting treasures and destroying them. You will need to use your tractor beam to pick up treasures and then transport them back to the research vessel without losing any of them. The game also features multiple levels, each with its own set of challenges and enemies.