The series's main distinguishing feature is its emphasis on global travel by sea. Eiji Fukuzawa first devised Uncharted Waters to offer "romantic freedom and adventure" during the prime of medieval discovery, granting players the option of choosing their fate through sailing. Like most Koei historical simulations, this means censoring or omitting many of the harsher realities of the era to fit with this theme. He hopes players will continue to experience the same thrill as the first explorers did in any series's entry.