Complete the following achievements to unlock Xbox Live Gamerscore points.

Achievement	How to unlock
High Society(25 points)	Go undercover to follow a lead.
King of the Castle(15 points)	Win a prize at one of the arcade games.
Last Resort(50 points)	Stop an out-of-control scheme before it's too late.
Perfect Host(10 points)	Throw a party for your friends.
Priority Target(25 points)	Discover a plot against you.
Simulated Hero(25 points)	Score 9999 points in the combat simulator on Normal, Hardcore, or Insanity.
Team Player(25 points)	Infiltrate an enemy stronghold with your crew.
Technical Issues(25 points)	Investigate a strange occurrence in the combat simulator.
The One and Only(50 points)	Defeat a group of Spectre-level opponents on Normal, Hardcore, or Insanity.