Wind Waker is not really an open world game imo, although it does a good job at faking it. Yeah, technically once you get the boat you can sail to whatever island you want, but you can't really DO anything at most islands. Most of them require some item in order to accomplish whatever you need to do on it. That is not like a true open world game where you can go anywhere and do anything regardless of level or items right off the bat. I mean, in the original LoZ, if you are really really good, you can clear some of the highest level dungeons as soon as the game begins. That cannot be said for Wind Waker.