Cupcake
10Beat 5 advanced chambers
Unlocked: 24 Nov 2018 00:02:01
Cause a rocket sentry to destroy its own rocket when the rocket has been redirected back towards it.
Unlocked: 07 Jun 2017 16:10:07
Knock a turret over with a security camera.
Unlocked: 29 Dec 2015 13:00:05
Win a gold metal on a challenge map.
Unlocked: Offline
Dissolve a turret.
Unlocked: Offline
Once you have control of both portals, only enter the orange portal.
Rat's Tale
15Find all the Rat Man dens.
Complete the game without ever taking a bullet.
Like a Rat
20Trap yourself in a test chamber so that GLaDOS has to help you continue.
Find the chicken's test results.
Fruitcake
25Beat 10 advanced chambers
Beat all advanced chambers