A surprise to many, Black Flag was the AC2 to 3's AC1, aka it took a gameplay aspect from the previous game (ship combat) and refined it into a iconic and enjoyable experience. The meta-commentary on game development served up by the story is refreshing (and particularly ironic given the state of Ubisoft at the time), while the focus on the piratical aesthetic is somehow not incredibly corny. In that light, it functions remarkably well as a standalone game outside of the AC series.