Master each of the weapons. Trebuchet, Centrifuge and Cannon. Master the ultra-real 3D physics of each of these weapons. Campaign through the land of Castle Canyon capture the flags and save the citizens. Then put the citizens to work for you in order to continue.
Efficiency, and accuracy are key to conquering Castle Canyon.
Trebuchet - use the trebuchet to sling various projectiles
Centrifuge - spin the centrifuge and release the projectile at the correct angle.
Cannon - load the cannon and let it rip.
Collect flags and save the citizens from oppression.