Complete the following achievements to unlock Xbox Live Gamerscore points.

Trophy	How to unlock
Air Kill (40 points)	Kill An Opponent In The Air.
Destruction King (20 points)	Win Ten Online Destruction Games.
Don'T Touch Me! (20 points)	Win A Race Without Getting Killed.
Firebooster (40 points)	Kill Ten Opponents With Every Fireboost Type.
First Steps (20 points)	Complete All Challenges For One Character.
Massacre (20 points)	Kill Ten Opponents In One Race.
Online Endurance (60 points)	Finish Fifty Online Games.
Online Racer (20 points)	Win Five Online Races.
Serial Killer (40 points)	Get 100 Kills.
Threepeat! (20 points)	Complete All Challenges For Three Characters.
Triple Kill (40 points)	Kill Three Opponents In 5 Seconds.
Winner (60 points)	Complete All Challenges For All Characters.