This is a very unfair comparison... It's like telling one person to build a house and the other a castle singlehandedly in a limited time. And then you compare the finer details like how well painted the walls are... Obviously... The Castle might not have the finer details as refined due to lack of time/resources...
Assassin's creed 2 is an Open World game... you should compare it to Prototype, Infamous or even World of Warcraft. It's a really awesome game.
I am a Gamer... I play games and not consoles. I have a PC and Console on which I game... I like games. End of Story!







