Professor Portal
After completing co-op, complete Calibration Course online with a friend who hasn’t played before
10/10/2012
6:21:08 PM
Ultra Rare 1.7%
Asking for Trouble
Taunt GLaDOS in front of a camera in each of the five co-op courses
10/9/2012
8:57:27 PM
Very Rare 6.0%
Party of Three
Find the hidden companion cube in co-op test chamber
10/9/2012
8:49:03 PM
Ultra Rare 2.9%
Portal Conservation Society
Complete Chamber 3 in the Hard-Light Surfaces co-op course using only 5 total portal placements
10/9/2012
8:23:11 PM
Ultra Rare 2.1%
Four Ring Circus
Enter 4 different portals without touching the ground in co-op
10/9/2012
7:29:27 PM
Ultra Rare 4.6%
1 week
Win all the EAS FC Match Day Games of the Week in a single week
10/7/2012
2:03:15 PM
Ultra Rare 0.4%
Untouchable
Complete all missions on any difficulty level without dying
10/5/2012
4:47:49 PM
Ultra Rare 1.1%
Demonslayer - Kill Radec within 20 minutes
Kill Radec at Visari Palace within 20 minutes
10/5/2012
4:42:45 PM
Rare 19.6%
Professional - 3 revolver headshots in a row
Get 3 headshots in a row using the same clip of M4 Revolver ammunition
10/5/2012
2:04:37 PM
Ultra Rare 2.3%
Killing Spree - Kill 5 Helghast in 15 seconds
Kill 5 Helghast in 15 seconds whilst on foot and maintaining at least 85% health
10/5/2012
1:27:55 PM
Rare 39.3%
