The movie plot felt like it was condensed, or that it could've been explained a bit more. I also felt you needed to play the games to really understand everything, and as an avid AC fan, I did enjoy the movie with all of the game references, but I doubt non-AC fans would really get into it. My main disappointment is that the script didn't allow for more character development and backstory, which I understand it would be difficult to do when you are trying to jam the characters of the Spanish Inquisition and the characters of the modern day, as well as the whole backstory of the Assassins vs Templars and pieces of Eden... Is probably just too much to do in one movie. I do hope that if there is a 2nd movie, they spend more time developing and getting to know the characters as well as even the simple things the games explained, like just why you have to assassinate said person, etc.
"To do all that one is able to do, is to be a man; to do all that one would like to do, is to be a god." - Napoleon I