You follow Connor from childhood into the adult seeking vengeance for killing his mother and constantly torturing his village. Along the way you are mentored by master assassin, Achilles Davenport, who pushes you towards missions and lets you take over his homestead.
The economy in AC3 is different than the other games, you actually have to work for your money instead of collecting it from the bank. At your homestead you help passerby's and extend stay as long as they agree to sell you their leftovers. With this you buy and craft items to sell to local shops you find along the game. Crafting is pretty neat, if you have the recipe, supplies and the right people in your homestead you can get items for cheap. Keeps these or sell them, it's up to you. It takes a little getting used to how everything works but once you get it down you will be a master businessman making bank in no time.
Combat in AC3 is still pretty simple and once you figure out how to chain kills you can start taking down groups of enemies without taking any damage. If you screw up your chain or someone hits you, I found it extremely hard to get back into rhythm and instead would run away then come back and start the chain over. The kill animations in combat keep you going and make you look pretty awesome when friends are watching.
Something that was added to AC3 that I feel is a plus, is hunting. You can hunt any animal you see from rabbits to, moose, to cougars. Tracking, setting up traps and fighting when the animals fight back. It's really fun to just run around hunting, skinning and selling the furs to the local shops to make good money. With this there is good ways of killing the animals and bad ways of doing it. An example would be shooting a wolf, this will damage the pelt and you won't make as much money when selling it.
Another cool thing that was added was your boat. There is a mission where you take it out for a spin and get a crash course on being the captain, not long after that you are being chased by pirates and have to defend your vessel. Things like this is what I love seeing in the game and what has made it one of my favorites.
Like I was saying with everything you can do in the game, I mean everything (I don't know how they fit it all on one DVD), there are little issues that bothered me a little. During the cut scenes you are always wearing the standard Assassin's garb. The way to equip new clothing is a little hokey. In your stash area, there looks to be racks where clothes you have purchased looks like they should go, but they were never there. During some missions areas are blocked off limiting the paths you can take where I thought it shouldn't be. Lack of instruction on how weapons were used. The rope dart, being the biggest culprit. The instructions popped up briefly then went away and I didn't catch them. I had to look online on how to use it. The hidden blade didn't work the same way it does in the other games also.
Other than what I said above and little glitches, this is the funnest Assassin's Creed in the series and I highly recommend you to pick it up, especially if you are a fan of the series or are on the fence about it. You won't regret it!