Load the achievements the logged in user has already achieved or reported progress on.

//JavaScript
	function Start () {
		Social.localUser.Authenticate (ProcessAuthentication);
	}
	
	function ProcessAuthentication (success: boolean) {
		if (success) {
			Debug.Log ("Authenticated, checking achievements");
			Social.LoadAchievements( function(cache) {
				Debug.Log ("Got " + cache.Length + " achievements");
			});
		}
		else
			Debug.Log ("Failed to authenticate");
	}

//C#
Social.LoadAchievements (achievements => {
		if (achievements.Length > 0) {
			Debug.Log ("Got " + achievements.Length + " achievement instances");
			string myAchievements = "My achievements:\n";
			foreach (IAchievement achievement in achievements)
			{
				myAchievements += "\t" + 
					achievement.id + " " +
					achievement.percentCompleted + " " +
					achievement.completed + " " +
					achievement.lastReportedDate + "\n";
			}
			Debug.Log (myAchievements);
		}
		else
			Debug.Log ("No achievements returned");
	});