Beat all advanced chambers
Trap yourself in a test chamber so that GLaDOS has to help you continue.
Find all the Rat Man dens.
Once you have control of both portals, only enter the orange portal.
Complete the game without ever taking a bullet.
Cause a rocket sentry to destroy its own rocket when the rocket has been redirected back towards it.
Find the chicken's test results.
Knock a turret over with a security camera.
Beat 10 advanced chambers
Dissolve a turret.
Beat 5 advanced chambers
Win a gold medal on a challenge map.
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