Destroyer is a 2D naval simulation. Players take the role of a captain controlling a United States Navy Destroyer class vessel. During World War II, the player has to command several Destroyer operations:
In each screen, the joystick is used to control the functions within that screen; for example, directing the heading and speed of the ship, or aiming and firing guns. Only one screen can be controlled at any one time; however, there is an informational ticker along each screen where certain stations could report informational updates, such as if enemy planes or submarines are sighted. Each mission was played in real-time, so the choice of screen at any given time is important, and switching between them rapidly is part of the strategy.
- Subhunter missions
- Rescue missions
- Blockade runnings
- Bombardment missions
- Scout operations
- Convoy escort
Attacks from enemies can disable any screen at any time. If a certain area of the ship is damaged by an enemy attack, the player can still access the screen, but all or part of the functions of that screen may be unresponsive. For example, if any of the weapons are damaged, they may not fire at all, or they may still fire but may not be able to be properly aimed. Damage to the navigation area causes the ship to sail uncontrollably in random headings. As battles progress, repairs—over which the player has no control—may restore functions. Some weapons have certain limitations that if reached could cause damage as well; anti-aircraft guns, for example, can overheat if fired continuously for too long, rendering them inoperable until they cool down. If the ship was to sustain too much damage in the course of a mission (or in certain other circumstances, such as running aground on an island), the ship was deemed sunk and the mission was a failure. Players also had the option of sending an "abandon ship" message, but in terms of gameplay, the result was the same as a sunken ship.