Nothing new... but still a great game all together.
There has been new weapons added and all missions have the ability to run through it various amount of ways, add replay value of the game really well. Although nothing had really changed from previous titles the game all together is still great.
The level detail in some maps are gruesome and pulls you into the life of a Hitman. You travel all over the world assassinating weird looking villains in the most satisfying ways imaginable. Bullet through the head, poison, bombs, you can do almost have you desire. The ranking system hasn't really changed that much, but the system confines you always to attempt to achieve 'Silent Assassin' which isn't sometimes always fun.
The game is ambitious in trying to make it more immersive although it didn't reach what it intended to be it is still a pretty solid game.