Assassin's Creed: Brotherhood expands upon the second game while forging its own destiny with excellent results.
The gameplay of Brotherhood largely remains unchanged. Indeed, Ezio has even more moves at his disposal this time. In addition to everything he had in the second game, he adds new mechanics such as poison darts, a crossbow, and some enhanced fighting mechanics like being able to fire his gun in the middle of swordplay.
Of course, the largest and most prominent of game additions is the Brotherhood mechanic itself and multiplayer. After a certain point in the game and after reclaiming specific territories, Ezio is allowed to recruit and train assassins. Training them either entails sending them on missions where they obtain experience, items, and money, or using them in combat to fight enemies. Obviously, sending them early on is advised as they lack gear and weapons early on. However, once they are fully trained they become as nearly lethal as Ezio himself.
It's not just fighting that they are good for, but also stealth kills as certain missions have parameters to obtain full sync. These can be as simple as completing in a specific time or as hard as fighting a squad of soldiers without losing any health.
The multiplayer is quite interesting as well. Because of the way that Assassin's Creed is designed in general, you are taking on contracts to kill other players. This is made even more challenging because while you are searching out someone to kill, someone is also searching out you as well. These cat and mouse games work wonderfully within the system and you have a variety of characters to choose from.
The only real issues I have with the gameplay is the learning curve is getting to be quite steep. This is definitely not the game to start playing the series, not just from a continuity perspective, but also from the sheer amount of things to learn. Also, there are still a few lingering camera and control issues that have been there since the beginning of the series. These are usually when you are forced to jump in the opposite direction while clinging to a wall or trying to jump from a pole where you can't see correctly.
Visual and sound design is excellent as it has been for the last two games. All of the previous voice actors have returned and the music is a foreboding, dark ambiance that stays with you as you play. The graphics have seen a bit of a overhaul as well. The characters look a bit more detailed and at least one has been redesigned almost entirely.
My feelings on this game, however, are a bit mixed. While the core gameplay and additions to the series are wonderful, the narrative seems to have suffered this time around. While the value is still immense as you not only have the main quest but all of the side quests, multiplayer, trophies, and other goodies, certain things feel weaker.
Mostly this is story related. A few of the most memorable characters from the second game like Da Vinci have been reduced to near bit parts. The game plays a lot more like Grand Theft Auto and while the non-linear style it is taking does give more freedom, it seems like it's weakening the story overall. Still, the game is definitely worth the purchase.
The Good: Excellent graphics and sound, maintains great continuity while sacrificing none of the second game's fun, good multiplayer, massive free roaming environment with tons to do.
The Bad: A few lingering camera and control issues, narrative suffers some from the second game.