I consider myself an avid gamer. I was excited to play the original Assassin's Creed, and loved it. However, it seems like every game afterwards has been more of the same. I never finished the second one, didn't bother to even pick up the third. This game stood out to me as an Assassin's Creed that was completely different, and didn't disappoint.
It still has the same issues that bothered me about the series, such as the free running controls. It seems like the game simultaneously tries to do multiple things at once, and usually the game chooses the wrong thing. I can only run up the wall to the right, when I wanted to jump over the handrail in front of me, so many times before I want to scream. Other than that, the game plays incredibly well. The ship in particular is amazing to me. It's awesome to get behind that ship's wheel and just pick a place you want to sail. Battles with the ship are fun and vary in difficulty quite well. Even choosing to go whale/shark hunting is an aspect that is unique and quite fun.
The hand to hand combat, while fun, is still a bit too simplistic for me to love. However, that is just the same system that they have chosen to use since the original game. In my opinion, the game could really stand to use a combat overhaul, but for all intents and purposes, it works good enough to remain fun and not diminish the gaming experience. The ship battles on the other hand, are done very well and very fun in my opinion.
While I still find the "time travel / memory" elements a bit too weird, out of place, and immersion breaking, the story in general as it pertains to the Pirate story is quite good.
The missions are another part that the game clings to hold on to "old" elements that made the game successful. The following, eavesdropping, etc missions are old, and tired, and need to be replaced. It seemed to be too much "assassin" and not enough "pirate". While I understand the "if it isn't broke, don't fix it" approach, it is immersion breaking to hold on too tightly to elements that aren't really part of this particular game. I felt there needed to be more theft, and robbery, and less follow / sneak / stalk. But being as how "that ship has sailed" (excuse the pun), it still remains a fun, exciting, and different experience than I have experienced in quite a long time.
All in all, this game is a must have in my book for any "adventure" seeking gamer, role playing gamer, or just for something different. I've spent many hours enjoying this game, and will spend many more. I hope there is another installment of this type, and I hope they choose to lose some of the old diminishing aspects in favor of a more dedicated system for a game that I think, deserves it.