I'm going to be cheap and just paste my impressions from my blog...
I bought Assassin's Creed yesterday and I was very impressed. So impressed that I played it for seven hours straight, without a hint of boredom. The free-running mechanic is so well executed that it makes up for the lesser combat system. Any of you who have read the reviews will know that critics have not been digging the combat system in the game. To be fair, after seven hours I didn't see any issues with it, and it didn't feel repetitive or tricky.
One thing I don't understand is why Ubisoft were so tight lipped about the game's futuristic plot twist. I mean it happens right at the start of the damn game, and I find it so stupid that we're all holding back saying "I don't want to spoil it for you." It's hardly much of a plot twist if you bump into it minutes after you start playing. What Ubisoft should have remained tight lipped about is how great this game was going to be, maybe then it wouldn't have been so hyped and eventually receive lower than excepted scores because critics were disappointed that the game wasn't the best thing to happen since Ocarina of Time.
The game has a Metroid style opening, where you start with all your abilities but due to a series of events you lose them all and must start from scratch to retrieve all the awesome moves and equipment you started out with. Ubisoft have added a silly optional achievement unlocking quest where you must find hidden flags in the game. It's like hidden packages from Grand Theft Auto games, except there's more flags and it's more annoying. I also hate it when guards randomly detect me when I've done nothing wrong yet, I don't know what I do sometimes that triggers them.