You will select a hero with unique abilities. As you defend your castle, you will earn money and loot. This will allow you to upgrade your castle and recruit AI controlled allies to synergize with and equip them with weapons and relics. You may also choose to allow the AI to control your hero.
Your movement is controlled like a mouse cursor. You will earn money for killing enemies which will let you pay for weapons and spells. Mix and match magics to convert this bullet hell into a bullet heaven.