Audio:
Great sound track and pretty good voice acting as well make this one of the better parts of the game.
Visuals:
Many noticeable bugs and glitches. Not much variety among the environments either, Everything looks the same no matter where you go. Visually, It's some-what appealing but boring to look at.
Game Play:
It's your typical Assassin's Creed game play. Nothing has changed from previous installments, Which is disappointing but also a good thing. If it ain't broke, Don't fix it.
Other:
The story isn't all that interesting. Missions are very boring and are based around doing the same objectives over and over again. Plenty of pointless collectibles. Ship battles start off as interesting and unique but quickly become a tedious task that isn't worth doing. Multiplayer suffers from lag and hasn't been expanded upon. Filled with frustrating and cheap deaths. Platforming doesn't always work the best either.
Overall: 6/10
Black Flag had potential but it seems they focused too much on having this huge visual experience rather than adding any real content to the game. What content there is is very tedious and boring. This game doesn't even come close to matching previous entries in the series.