PCG421 Trueblood: The Karthanian Ultimatum

As you progress through the game two bonus levels allow you to pick up 
additional lives, lasers, and shields.  It is likely that you will need 
them.  As you get closer and closer to the Karthanian stronghold, you will 
eventually be called on to destroy the Karthanian base, called The Citadel.  
It will take many shots from your weapons to destroy this.  When you score 
a hit it will change color for a brief instant.  As part of its defenses 
The Citadel rotates, and Karthanian warships will come at you in waves in 
an attempt to drive you off.