It's an interesting game. But there seem to be some balance problems. To destroy the third castle in a pack, you need to use multipliers, because the multipliers and last castles are too strong. The only way to get multipliers at the beginning of the game is the Mage cart. There is some multiplier bonuses, but you can't buy them because you'll die before you can to save up enough money due to bad luck and not getting the Mage in combat. Maybe you could add more than three castles to the pack?