After launching the Uplay service with Assassin's Creed II in 2009, Ubisoft has included the service in several new releases. It is available on the PC, PlayStation 3 and Xbox 360 so far.
Each game has 4 achievements that are unlocked as players progress through the story. Each goal earns Uplay points, abbreviated simply as U. These points are used to unlock game related awards.
You can also use the Uplay service called "Assassin's Creed II - Web Battle" to view list of in game statistic and to get additional web-based achievements and rewards.