This entire game feels like one big mini-game. You find yourself repeating the exact same missions over and over after the first 3 levels.
Further to this, the combat system is too simple, the weapons are pretty much all the same, and there is no real advantage to planning your attack; you may as well rush in and kill everyone rather than using stealth.
Add to this the difficulty in the later levels of the game are based on adding more guards, and making them more alert, which slows down the game, but doesn't make it too much harder (honestly though, sometimes you'll be minding your own business walking along and a guard will pick a fight for no discernible reason. This is really annoying when you have to stay out of trouble on some missions (because getting anywhere in stealth mode is REALLY slow).
The "parkour" movement is quite good, and enough to get it up to 2 stars, but not enough to keep you interested.
The whole game seems rushed, a prime example being the flags available for collection, however there's no point in doing it; you get nothing - not even a trophy - for your troubles.
The story that people seem to rave about rarely comes to life and could have been written by a 5 year old (an intelligent 5 year old, but a 5 year old nonetheless).
I dislike not completing games, but even though this one is pretty short, I had a lot of trouble motivating myself to do it. DO NOT BUY.