pro
The story of Assassins Creed 3 wraps up most of what has been going on with Desmond. The buildup in the first 5 hours sets the tone for a well told but not amazing story that involves you meeting a lot of brilliant personalities and being in the middle of some great set pieces. It also plays a lot better than earlier iterations with tighter controls and impressive animations. You still find yourself looking silly while jumping into a wall that you can't scale over and over again, but you will rarely accidentally jump off a cliff or tree that you didn't mean to this time around. Pointless stuff like tower defense games and weird first person Desmond-sections are gone, leaving things to do that actually feels somewhat relevant.
pro
Assassins Creed 3 is huge. As with previous games it has cities bustling with more life and day to day routines than ever before. All of this plays second fiddle to the amazing frontier though, which lets you scale and traverse trees while looking amazing doing it. Hunting animals and enemies from the treetops often results in some truly satisfying takedowns.
pro
The naval gameplay is simply fantastic. Watching the crew hard at work while you're maneuvering a giant ship in the middle of a raging storm is so impressive and immersive it could almost warrant its own game. The sense of weight and scale in these situations is a work of art.
pro
It's no surprise that there is a lot to do when you need a break from the main story missions. While chasing flying pieces of paper can get frustrating, going on a big treasure hunt is some of the most fun I've had with side missions in Assassins Creed ever. Homestead missions and solving mysteries out in the frontier are also great examples of stuff that doesn't really get old as you're progressing.
con
It is a real shame that the first hours of the game are so severely underplayed later on in the narrative. The story as a whole becomes somewhat less interesting as it's getting closer to the end, leaving us with a rather underwhelming conclusion to what has at times been an amazing story arc. The scale of what has been shown in trailers and previews does not necessarily translate into the final game.
con
The lack of polish can be rather annoying. There are glitches and bugs throughout the game that ranges from unintentionally funny to mission breaking. Suddenly getting attacked by what seems like every guard in town completely unprovoked is just grating. I completely understand the point made that finding all the bugs in a game this huge is impossible, but that point loses weight the minute you realize they spent resources creating a mini-game for breaking up a fight that you only do once in the entire game. Perhaps that time could've been spent better elsewhere.