Introducing social stealth and an interesting protagonist.
The game has two different storylines or layers in it. First is the present where you play as Desmond Miles, a bartender that has been taken as some kind of prisoner in a weird experiment or investigation: he has to place himself into a machine called the Animus, which allows one to see into his own genetic memory. In this case it means that most of the time you will play as Desmond's ancestor Altaïr ibn La-Ahad (The Flying One, Son of None in Arabic according to Wikipedia) in Middle-East during the Third Crusade, which is to say around 1191 AD. Altaïr has to assassinate 9 different influential persons, but all the time he has the feeling that there's more involved than just these simple assassinations. This game is the first in a new franchise and unfortunately you can see that in the story: Altaïr's story comes to a moderate conclusion, but Desmond's fate leaves the player guessing. In some ways Assassin's Creed raises more questions than answers in terms of its story.
Graphics are great and after this I'm scared to play Zelda Twilight Princess again: it's just that good to look at comparing the regular Wii graphics. You have 3 big cities to explore (Damascus, Acre and Jerusalem). All of them are full of life and there are no loading times between different sections of the city. This gives the player a seamless experience just like in Grand Theft Auto and it is a good thing. There are hundreds of people walking in the streets, the draw distance is very good and still the frame never takes a hit. Or actually it did just once in the whole 10 to 15 hour experience.
Sound plays an important part in Assassin's Creed, because it needs to create an atmosphere of a living and breathing city and for the most part it does just this. Some of the dialog of the street people can get a little old after a while, but other than that there is no complaint about the sound effects or music. Unfortunately for some reason there is no subtitles what so ever and this is a huge disappointment, because in a story-driven game you obviously want to follow the story.
Gameplay is, as I said earlier, an open-ended exploring in a big city. Your job is to save citizens in trouble and to perform investigations in order to plan your assassination properly. These investigations are eavesdropping for info, pick pocketing maps and other intel and also interrogation, which means that you need to beat someone with your fists until he gives you the information you need. After this you will get your order, perform the actual assassination and escape. You'll notice very early that this is the pattern the game follows nearly all the way through and it can get a bit boring unless you play for example one assassination per game session.
In order to find points to progress the story you need to climb high up to a view point to get a wide view of your surroundings. It's here that you'll notice that most of the developing time has gone to a challenge of designing a big city. After getting the info from a view point you can jump down and land into a haystack. This feature of the game never gets old.
Social stealth is a new feature, which means that in order to escape you need to take cover or blend into the crowd. This is done either by joining a group of scholars walking in the city or by sitting to bench between 2 people. It's nice to hide in the open instead of always running into some dark corner.
The worse thing in Assassin's Creed is its combat system: it's clunky, slow and nearly unresponsive. In time you'll learn to use it so that you may finish the game, but it will irritate you all the way through. As soon as things get hairy and precise and fast actions are needed the game becomes a frustrating struggle. This game just isn't meant to be a fighting game, but unfortunately towards the end you'll find yourself more and more in big fights.
There are some annoying problems in Assassin's Creed, but in the end it's still an experience I recommend you to have, if you like games like Grand Theft Auto, Thief and Prince of Persia.