You get 5 content to unlock (Platinum Edition)
2 new single player missions
(The aqueducts and Tranjansforum)
2 new multiplayer characters
(The Harlequin and the officer)
1 new armor for Ezio
(The dragon armor)
For the game itself:
Graphics: 10/10
Story: 10/10
Fun: 10/10
Well worth buying !!!!!!