What is the difference between the Raider and the Bomber, really? How are a Raider and a SuperRaider different? Maybe they have a different speed, a different texture, and a different damage value? Do these changes in data really require a new class? Those are really just different values, not different behaviors. The problem is that we are creating extra classes because the concept of a Raider and SuperRaider is different, but there aren't differences in behavior.
Our class hierarchy actually violates three principles I teach, two of which I learned from the Gang of Four book:
"Keep your inheritance trees shallow"
"Favor object composition over class inheritance" - Gang of Four, p20
"Consider ...
