Page "Star Castle" Paragraph 3

Once the innermost ring has been breached, the central weapon is vulnerable to attack from the player.

However, the player is also more vulnerable at this point, as with the shield rings eliminated, the gun can fire out a large projectile that hisses with white noise.

Moreover, the central core tracks player movement at all times.

If the player manages to hit the cannon, it explodes violently, collapsing the remnants of the shield rings, and the player is awarded with an extra ship.

The next level then starts with a new gun and fully restored shield rings, with the difficulty increased ( the mines move faster, the rings rotate more quickly, and the core tracks the player faster ).