So i had a pretty good idea that is already quite advanced in the development. Basically, you are a pirate captain and your crew is losing his trust in you. You loose your power as a captain by losing your crew, so you must keep your power on your crew by looting island and by attacking and looting other boat. idk if it really is respecting theme, but i like it so i will keep it. If your crew trust get to 0, the player lost. :)