Instead of building towers and defending against hordes of monsters, play the opposite as an evil mage that builds his army from the ground up to dominate the lands.
Build structures, train army, destroy enemy castles. Your soldiers will charge and break through enemy defense lines automatically and use magic to assist your corps assaults.
Aliens have infiltrated the naval command ship. You are the captain and you'll go down with your ship. The question is how many aliens will you take down with you?