Attacking ships got boring, way boring, because it got so easy too fast. The end of the game was also very unspectacular and abrupt, felt feeling quite pee'd off that the end was so, tame. The world it's in, is great, it looks phenomenal. The story was hit and miss, and as others, most of the stealth parts are, not very stealthy. Though this game had very little(from what I saw) get seen, de-sync, frequently it let you kill people quickly and get on with it. in fact at many times I just bum rushed entire strongholds. Other times I took out massive camps of people one by one without being seen.
It's not a particularly realistic game but, so what. There are incredibly frustrating missions, a few where you really can't be seen. But most of these let you get seen briefly but hide again without trouble. The irksome thing is when you're running, you know you can make it around a corner and out of sight fine, but it randomly decides you're too close to some wall and run up it and get stuck on it instead of around the corner hidden.
A few bugs, none too major but a couple fairly irritating, assassination targets going missing from the game world completely.
Combat is too easy, the little irritating slow as loading screens are find the first time, serial killer rage inducing later on. Can't say the number of ships I boarded, the number of flags I had to chop down. It was beyond repetitive, because there was no challenge and basically two types of enemy there was no challenge. If it was challenging that would be one thing, when it's not, it's just irritating.
I didn't get killed once by an outpost, and outside of one legendary ship killing me a few times in a row till I worked out a tactic, at which point it became trivial.
The world really is stunning though.
What you miss in games is going through one of these levels, through some stunning cove, up into a island to some ruins, and you can see down back to the beach you were at before. The draw distance was great, the quality of the entire scene in those moments you can look down and see where you've been makes the game that much more immersive.
It could be a whole lot better, it could be a whole lot worse.
I'd say, less ships, more reward, have a quick mode boarding or something where you get 75% of the reward but lose a few men so you have to board now and then to buy crew or occasionally recruit crew members. There were almost entire mechanics unused in the game. Huge amount of cash later on and completely worthless island upgrades to spend it on? A home base that is never really involved in the story except trivially. You could buy crew members but never once did I come close to requiring it, you can quite easily take on an entire fleet of ships, and the boarding mid battle to repair yourself is a stonking great big cheat. No upgrade for ship speed in travel... despite ridiculous amount of cash.
Despite running at wanted level 4 for almost half the game I never faced a difficult battle with hunters, they always appear behind you, and are never faster than you.
Combat was too easy and, there was I don't think a single time that you needed the extra muscle or camouflage of the pirates/hookers. Lastly the story could have been better paced, and had more complex levels, more platformer style climbing/jumping to moving platform sections. Though many of those were frustrating in other games, it's another challenge that was completely absent in this version.
I'm completely fine with AC moving on, it's moved on to different time periods and I have no problem with that. But more variety in what you do would be useful. Every assassination, every convoy, almost every level were the same things, sneak around in bushes to get to a target to kill with a few trees to jump through. LIttle to no secret hidden caverns. The underwater bits were tiresome and irritating, short and not very fun and no where a replacement for hidden tombs and climbing up huge buildings looking for treasure, etc, etc.