Although it's repetitive and has a slightly incomprehensible story, AC has many elements that will suck you in.
Graphics (8.5/10):
The cities of the Middle East during the 12th century are BEAUTIFULLY re-rendered. Not only that, but everything is explorable. The textures are also pretty good looking. The only downer are the character expressions. They either ALL look angry or totally expressionless. Other than that, the graphics are pretty good.
Sound (9/10):
The sounds are pretty good in AC. There was only one flaw I could find. Everyone, except Altair, Doc, Altair's lineage, and the Doc's assistant, all sound the same. You're probably saying to yourself so what? That's all of the main characters, I don't care about any of the other characters. But trust me, you do enough interaction with other people that it gets pretty damn annoying. But overall, the sound is pretty much flawless.
Game play / Storyline (9/10):
AC is what makes a next-gen game...well...next-gen. With elements of Action, Adventure, Stealth, Platforming, RPG, and even a little bit of Shooter, it pretty much blends these together seamlessly and is amazingly able to pull these off smoothly. Of course, every game has it quirks. Running through a city or galloping on your horse is aparantally unacceptable social behavior, and that will have the guards on your tail as fast as you can say WTF. So it takes extra time to go through a city. Another small downer is weapon choice. You only get five (I'm including the throwing knives). You can't pick up enemy weapons, which I wish you could, but the arsenal you are given is enough to assassinate even the toughest of criminals. The framerate lags slightly when there are a lot of people on screen, but it's not very noticeable. Possibly the biggest con is repetition. Travel to some far off distant land, investigate, kill, run. Travel, investigate, kill, run. There's nothing that really keeps it fresh and unique. You do the same stuff throughout the whole game. Finally, leaping from building to building eventually causes you to take a nosedive right into the dirt, which is pretty annoying. But AC is only about little quirks. The good definitely outweigh the bad. By a lot. The action will keep you going for HOURS. The combat is pretty easy to pick up on. Doing investigations are fun and really give you that feel of being an assassin. As for the storyline, the game would of been GREAT without the whole futuristic side to it. But then again, Ubisoft needed some element in the game to lead up to a trilogy, which they plan on making. Oh, btw, the ending is really lame. But other than that, the whole past part of the game is really immersive and has a great story.
Lastability (8/10): With no multiplayer, Assassin's Creed pretty much hits your dust collection drawer in a matter of a month or two. Once you beat the game, you can always go back into a previous chapter and collect the flags and stuff, but you can't really do anything else. Now if only you could kill whoever you please, that would make it better.
Final Comment: Assassin's Creed does a pretty good job at combining some of the most popular genres out there. The game would of been really good if it weren't for the whole futuristic part of the game. Gameplay is really fun and immersive, but does have some quirks. Overall, Assassin's Creed should be picked up by any gamer as it will satisfy anyone. An 8.5 out of 10.