Minako is kind of like a tower defense game. The goal is to defend your castle for 30 nights. To do that you need to hire local villagers and assign them jobs.

The key to victory is to keep in mind each villagers stats and skills and assign them accordingly. For example villagers with high strength will do better collecting wood or iron and will fare better on the front lines of battle. But it's not as straight forward as that.

Keep a sharp eye and observe them well to develop your own strategy.