Sub Killer!

Sub Killer! is a 1-player arcade game for the BBC Micro.

The player controls a ship atop the water that moves left and right, while submarines race horizontally below. Submarines launch torpedoes that the player must avoid, while also dropping depth charges to try to hit the subs. If the player is hit three times it's game over. When all subs are destroyed the player moves on to the next more difficult level. The player can set game speed from 1–14.