Complete the following achievements to unlock Xbox Live Gamerscore points.

Achievement	How to unlock
Bathed in Glory (60 points)	Obtained all Awards.
Co-ordinated Fire (20 points)	Completed any Level, in any difficulty, in a 4-player co-op game.
Grizzled Veteran (60 points)	Completed all 4 Levels in 'Nightmare' difficulty mode.
Jack of all Trades (30 points)	Obtained Rank 5 in all 4 XP categories.
Juggernaut (40 points)	Within a single session, obtained at least 6 Awards in one Multiplayer round or one Campaign level.
Level 1 Complete (20 points)	Completed Level 1 in any difficulty mode.
Level 2 Complete (20 points)	Completed Level 2 in any difficulty mode.
Level 3 Complete (20 points)	Completed Level 3 in any difficulty mode.
Level 4 Complete (20 points)	Completed Level 4 in any difficulty mode.
Master of all Trades (60 points)	Obtained Rank 10 in all 4 XP categories.
Seasoned Pro (30 points)	Completed all 4 Levels in 'Normal' difficulty mode.
Small-Arms Specialist (20 points)	Completed any Level, in any difficulty, using only the Piranha.