Loved it from start to finish...
My favorite part of this game is the fact that it's a free-roam that doesn't have the usual loading screens, you can go around the whole map without having to wait, unless your entering a new city. You can get to a high perch and see almost the entirety of the city, take a look to see if you can spot some flags, and then plunge to ground with a nice swan dive.
With missions that never get old and a striking, dual story line, this game keeps you enthralled until your eyes hurt at 4 in the morning, and still keeps you awake to kill that last target.