Can't enter buildings, lack of A.I. interaction, and only environmental object to affect is haystacks?

There's a lot of things awesome about this game, but that awesomeness is confined to a smallish scope, severely limiting the player.

I agree.  And as Andrew said ^^ a few other things keep AC from being truly great.  It is still a very fun and enjoyable game, especially for someone like me, that doesn't have the ability to play online.

Despite the criticisms I think Im going to pick it up. I watched my friend play a while and I was pretty impressed. I don't mind repetitiveness in games as much as others so that shouldn't bother me much.

I just finished the game. I have to say, Assassin's Creed does a great job of giving you options for taking out your target. I read one review that it just boiled down to mashing buttons and engaging the target in a fight. I have to wonder what the hell were they doing? Did they even bother getting all of the info available? If they had they would've found the proper way to get in and stealth kill. The game gives you choices. If you don't want to take the time and know all there is about your foe, then you may have to take your chances in a fight. If you play it like an Assassin, you won't.

I definately had a blast with this one. Going to go for some of the extra achievements for it tomorrow.

I'm still playing the game. I had to stop for a while because my life was just getting too damn busy. But I continued playing a couple of days ago (Thursday) and it's still really fun, though still really repetitive. I don't know. Just my feelings on it.

Is repetition so bad when you're having fun? Guitar Hero is nothing but repetition and that game's a blast to play.

I rented it and--as I expected--I wasn't impressed nor did I find any aspect of the game entertaining, sure it's original the plot is above average and it can be fun at first but there wasn't enough substance to keep me playing it for more than two days and felt way too repetitive for my taste.