Polaris

Polaris is a 1-player vertically scrolling arcade game for the BBC Micro.

As the commander of the Polaris submarine, the player's mission is to sink enemy shipping. A convoy of cargo and warships are approaching from the top of the screen. The player can move in the cardinal directions, fire forward and aft, and surface or submerge.

Enemy barrages appear near the player, and if the player is hit 6 times their ship sinks. The submarine is harder to hit while submerged, but must periodically come to the surface for air. As the ship is damaged it may develop malfunctioning torpedo tubes, engines, or air valves.