Since AC2 these games have been about building your own economic empire, so AC4 wisely admits that you were playing a pirate all along, and makes the protagonist an appropriately greedy bastard. Of course Kenway would loot bodies, open random chests, get into a fight in every bar, take over forts, manage a fleet, and have a dedicated checklist button to make sure he doesn't miss a scrap of treasure.

Compared to AC3, the cities are less atmospheric and more functional. Fewer bespoke animations for NPCs and blending, ambient music replaces ambient noise and dialogue, and crowds move in big chunks like AC2. Again this fits with Kenway's character! He is not a guy who stops to smell the roses, He's rushing from one objective to the next to get rich as quickly as possible.

Social stealth is de-emphasized in favor of stalking through the bushes, which means there is always room to keep moving. Enemy detection is much more forgiving, encouraging aggressive hit and run tactics that fit the pirate theme, and work very well with the speed of AC3's combat and traversal. Avoiding detection in a boat involves always moving forward, just changing directions when you need to. Even in stealth, Kenway is always thinking on his feet.

And that's the biggest strength of AC4: the scenario is so well-integrated with the gameplay. The historical figures all have the same job as you, so they can actually be major parts of the story rather than cameo appearances. Kenway is an outsider to the Assassin-Templar war who drops in and out of it at his convenience, just as the player can always choose when to start the next main mission, free of the obligations that bound Altair and Desmond. You don't have to pretend to serve the Creed anymore. Welcome to the Republic of Pirates.