Like stabbing dudes? Then you should probably play this.
There was a lot of rumor leading up to the games release that this would be a multiplayer centric chapter in an otherwise entirely singleplayer focused franchise.
Thankfully this is not the case and while the game does include a fairly enjoyable multiplayer experience, it is but a small piece of a fairly sizable puzzle.
Assassins Creed: Brotherhood is a direct continuation of the last game.
I don't think I'd recommend playing this without having played it, though you could read up the plot on a wiki I think you'd be better served actually experiencing Assassins Creed 2, which is still a fine game in it's own right.
If you've played the last game you should feel right at home, though some changes have been made for the better.
The combat has been streamlined somewhat.
In previous Assassins Creed games you'd wait for a dude to attack you, counter to kill them and then wait for the next guy to have a go at you. You'll still be doing a lot of countering, but if you press the attack button right after you've taken down that first attacker you'll immediantly take down the next nearest foe. And if you press it again, you'll take down the next. And so on. And so on. You string your executions together in order to take down large groups pretty quickly.
If you've played Batman: Arkham Asylum you'll have experienced a similar mechanic.
It's pretty satisfying.
Perhaps the other big change is the idea of the Brotherhood.
A little ways into the story you'll have the chance to recruit folk to your cause, who you can train as Assassins by sending them out on missions which acrue XP for them and money for you. This is all done by a handy menu.
Recruits also have a more practical application in the field, you can call them in to take out foes for you - though this ability has charges. It never the less makes you feel like a bad ass when you call in a dude to come in and stab the shit out of guys for you. You can have a total of three charges and when you have three charges you can hold down the button, so rather then calling in a dude to kill a dude for you - they'll just rain arrows in on the area, killing pretty much every guard on screen, which can be handy.
I don't know what else I can really say.
I like me some Assassins Creed and this is more of that.
Between the engaging, lengthy campaign and the multiplayer face and neck stabbing enthusiasts have plenty to be excited about.