Go for the Gold - 15 points
Win a gold metal on a challenge map.
Out of the Blue - 25 points
Once you have control of both portals, only enter the orange portal.
Rat's Tale - 15 points
Find all the Rat Man dens.
Is Anyone There? - 20 points
Complete the game without ever taking a bullet.
Saw That One Coming - 5 points
Cause a rocket sentry to destroy its own rocket when the rocket has been redirected back towards it.
The Camera Adds 10 Pounds - 10 points
Knock a turret over with a security camera.
Like a Rat - 20 points
Trap yourself in a test chamber so that GLaDOS has to help you continue.
A Feeling Like Floating - 5 points
Dissolve a turret.
Tests Like Chicken - 15 points
Find the chicken's test results.
Cupcake - 10 points
Beat 5 advanced chambers
Fruitcake - 25 points
Beat 10 advanced chambers
Vanilla Crazy Cake - 35 points
Beat all advanced chambers
