To win a level you as the Siege commander have to kill all the castle defenders and save the hostages by carefully choosing what supporting blocks of the castle to smash.
You can earn one of the three medals (Clear, Decisive and Brilliant Victory) and also you can loot each castle by hitting the treasure chest.
The fewer shots the better.
The Level Editor allows you to create and share your own custom levels.
Check the People's Empire to play the user submitted levels.
The bonus level unlocks at the end when all the previous castles are taken.