Rome Wasn't Built in a... Well You Know the Rest
ACB takes directly after the events of ACII. Desmond and his chums are still hunting the Apple of Eden. They set up the Animus in modern day Monteriggioni and we see our old friend Ezio, the protagonist from ACII, in 1500 enjoying his prosperity. In the first game you rebuilt Monteriggioni, you leveled up Ezio, things are going great until Monteriggioni is attacked by Cesare Borgia, a crooked general and son of Rodrigo Borgia (the pope and villain from ACII). Monteriggioni falls, Ezio is wounded and wakes up in Rome. Here he starts from zero ready to exact vengeance on Rodrigo and to obtain the Apple of Eden from the Pope.
Gameplay in Assassin's Creed Brotherhood is remarkably similar to it's predecessor. You still assassinate people, go on missions, collect treasures, feathers and flags. A tweak from ACII is you can now ride a horse in the city. Also, the rebuilding aspect from the first game has expanded. In the first game you would improve Monteriggioni by renovating the buildings. In ACB you do the same thing except you rebuild Rome. You renovate banks, art shops, blacksmiths faction buildings and landmarks and doing so earns you income. This game adds another gameplay wrinkle which is why the game is named, "Brotherhood." Let's just say that Ezio isn't the only assassin on the block anymore.
ACB also marks the first game to include multiplayer, which is enjoyable. There are several game modes but most of them involve taking out a target. The game is kind of like a game of hide and seek. You have to hunt your target down and assassinate them. The person being hunted has to hide from their attacker. Everyone has perks, some help you hunt your targets and others help you hide. This game is a fun change of pace from all the FPSes out there and a worthy addition to the series.
The graphics continue to improve from game to game. There is a noticeable refinement in the graphics compared to the previous games. Characters look better and the game runs smoothly most of the time. The whole game takes place in Rome, a huge open area, unlike the previous games that were divided, and there aren't really any load times since you can travel anywhere you want. There are load times if you do other missions and go to other areas but the game loads pretty quickly for the most part.
Assassin's Creed Brotherhood is a great advancement for the series. The game is improved in every way. I can safely say that this is the best game in the series thanks to the new gameplay tweaks and the addition of multiplayer. If you could never get into the series this game won't change any minds but if you're a fan of the series you're sure to enjoy playing this game