Subs

Subs is a 1-player arcade game for the TRS-80.

The player controls a battleship that moves horizontally, and can drop depth charges from either side of their vessel. These vessels sink slowly, and the player can have up to 5 depth charges on the screen at a time. Enemy subs sail under the water, and fire torpedoes towards the player. If the player is hit, they lose half their points. The player has 90 seconds to destroy as many subs as possible. If they reach 500 points, they gain an additional 20 seconds.