Deadly Tide is a pre-rendered shooter in which the player gets to control a deadly new undersea vehicle. The basic plot behind the game is that the aliens have arrived on Earth, and they are not friendly. They take up residence in the oceans of Earth, and begin to launch attacks on shipping. Plus, they are also slowly raising the level of the oceans, trying to flood humans from the planet. Your mission is to stop them. The game is split up into a number of stages, taking place in various locations, the ultimate aim being to make your way through to the end of that level in once piece. There are many cutscenes that advance the story.