During gameplay the cannon located in the center of the screen would "track" your ship and occasionally shoot a large energy blast at you which you needed to avoid.
As you would shoot the outer "ring", pieces would disappear, if you totally destroyed every "piece" of a ring, the ring would regenerate completely. The object was to create "holes" in all three rings in which you could make a timed. well-aimed shot at the center cannon. Some ring "parts" held "sparks" that once the part was shot, the spark would release and slowly chase your ship around the screen.
You could fly off the screen in any direction and instantly "warp" to the opposite side, also like Asteroids.
As was typical with Vector Graphic games of the time (Asteroids, Rip Off, etc.) there was no "color" other than the white vectors, so to add color to this game's screen a colored film was applied to every cabinet.
Star Castle's controls were similar to Asteroids. They consisted of:
- Rotate Left
- Rotate Right