In Assassins' Creed you play as a person playing a person in Renaissance Italy and that's what it feels like.
The setting is impressively detailed but the camera is always pulled out far and the vision is always on the next place to jump, failing to give you a sense of reality and impressiveness and made it is.
The characters aren't and the plot (with several impressively unreveal reveals) and it has all the draw of reading about someone reading a book. Several times you will be a bit unclear why you are going to a place and why you're doing what you're doing but it's okay, because you're just following disjoint markers and pressing buttons whilst Desmond plays fragments of Ezio's life.
Combat is reduced to waiting around for someone to attack you, pressing a button when they do, and watching your assassins kill the person off (albeit it in a very cool manner). The complexity added to this game is, sometimes you have to do it multiple times, or drop your weapon first, do it, watch the disarm animation and then repeat.
The economy is the method of you waiting round whilst the game showers money on you that can only be spent on earning more money and even without it, the game is easy. Health is pointless because if you lose it, hold the block button and wait for it to regenerate. Since countering involves holding block, only boredom will kill you.
If you make a mistake it's not your fault. It's Desmond's. Freerunning consists of holding two buttons and watching the character pick out appropriate places to run and jump. Sometimes he will decide to jump off a building instead of onto the next ledge and then you die and have to wait a few seconds and possibly repeat half a minute of mission. The challenge in freerunning is 1. Trying to control the camera whilst pressing a button with your right thumb. 2. Trying to step off a balcony.
Side missions often involve morally questionable activities, like helping someone cheat on two women, or recovering evidence on the behalf of an adulterer and soon to be murderer. You can only run to designated objectives whilst Ezio happily completes the task. You can't even fail, only pretend you never took the mission.
At the end of the game it appears that someone is speaking directly to the player. And then it turns out they're speaking to Desmond. It is a good game, but not for you