It's a great fun pirate game. They should have had the balls to just distinguish it from AC a bit more, and turn it into it's own franchise.
Not really sure how playing it gets you hyped for the next AC though. There have been 2 entries in the franchise since, both of which you played (and didn't like), both of which moved in a completely different direction from Black Flag. Now, obviously the next AC could very well turn out to be a great game, but there's no reason to think they'll suddenly go back and draw inspiration from Black Flag as they're making it.







