Upgrading to MAX LEVEL Fortress

It's Awesome Pirates. And the mission is to get yourself the biggest cannon you've ever seen. It's a mission that every man on the planet hopes to achieve, but few ever do... But I shall at least try. There's all these sussy pirates that want to destroy my fortress, but I won't allow them to do that. So I'll have to destroy them first which earns me money. I can use this money to upgrade my cannons. The bigger the cannon, the more destruction. It's perfect.