(Start of play: March 31st, 2012)
I've finally beaten the story of Brotherhood and here's my review.

Gameplay

This time you don't only spend a long time in the Animus, you actually have more gameplay outside of the Animus too. Like exploring the sanctuary in the beginning of the game. It's fresh and new. You can also exit the Animus whenever you want to explore the Auditore villa in the present. In the Animus you must choose memories yourself. If you do them in the right order and do a special objective, you will unlock certain things. You can now replay them whenever you want. If you take down a Borgia captain and ignite the tower, you can buy a piece of property for the whole city to use.
The best part is recruiting and training new assassins later in the game by sending them on contracts and upgrading them with skill points. You can then use them in battle against enemies.
The most awesome part is the Leonardo's Machines sidemission, where you get to fly an airmachine with a gun, control a tank and use a gattlinggun on a cart.

Combat system
The combat system has once again been improved. The guards have much less health now, which is good because it took forever to kill them in II. You can now kick enemies to disable their defences. Another great feature is that you can fire your gun while your sword is equipped by holding X. There's also the new execution streak which allows you to do multiple executions in a row.

Story
I really love what they did with the story in this game. It takes a few interesting twists and turns in the course of the game.
You even get to go to some of the places in the present that Ezio had visited in the past. The ending is very sad. (and Revelations makes it even sadder)

The beginning of the game with Ezio is great, he has sex with a red head c:

I give the game a 9 out of 10.