Can't wait for the sequel!
I never had such mixed feelings about a game. What Assassin's Creed is both unbelievable and flawed. Amidst the beautiful graphics, the silky smooth animation of Altair, great storytelling and excellent platforming is (at times) moronic enemy AI and repetitive gameplay. Though neither of the two should discourage anyone from playing the game. I would love to see some more variety in the future games of the franchise, but I still had a lot of fun doing the same thing over and over because it was executed so well. But it wouldn't have hurt to add some variety to the investigation missions. The elements are all there, they just haven't been mixed and matched enough. But this one can still be overlooked.
The enemy AI, however, is problematic. Why is it that a second guard does not react when I kill the first with a throwing knife in his plain sight? Why can't they obviously see that I recently killed a group of guards to save a citizen when I'm standing right there talking to the citizen. And most importantly, why isn't there any consequence of killing so many guards? Sure, the game ramps up the surveilance in later levels but I would have prefered a model where every city kept a tab on how noisy I had been in my previous visits. There should be a reward for keeping things quiet and a consequence of botching things up. Even in the assassinations, you can get away with botching up easily and take down the guy in combat.
These things held back Assassin's Creed. But in a way its a complement too. How? Because if the rest of the game did not shine so much... I wouldn't have noticed. This game has immense potential which could not be utilized because of, in my opinion, release dates! I'm quite sure a team good enough to make such a game would have noticed these issues. They probably just didn't have enough time to fix them.
But now they are working on the sequel, and I really hope they work them out (and that they bring Altair back... I think it's quite possible he may not come back)
I like how Ubi evolved every game of the Prince of Persia series (Yes I thought Warrior Within was better than Sands of time... and yes.. I think Godsmack made some sense there too in the larger picture which includes the Two Thrones) and I hope Assassin's Creed does the same!
To give some more structured scores:
Graphics - 10 (absolutely breathtaking stuff. There were points where I stopped just to gape)
Sound - 8 (Even if Altair had to have a American accent, it could have been done better)
Story - 10 (It's a great start, let's see where they take it)
Gameplay - 8
To sum up, when I first saw Assassin's Creed before its release, it became a compelling reason for me to get a next-gen console. After playing it, I was not disappointed! Nothing is true, everything is permitted... Ubisoft knew what they were getting into! Hats off to them.