Sacrilegious
Sided with the Cult of Andraste in "The Urn Of Sacred Ashes"
5/21/2011
8:12:45 PM
Rare 13.3%
Professor Portal
After completing co-op, complete Calibration Course online with a friend who hasn’t played before
5/20/2011
2:37:00 AM
Ultra Rare 1.7%
Triple Crown
Solve 3 co-op chambers in the Mass and Velocity course in under 60 seconds each
5/20/2011
2:09:38 AM
Ultra Rare 1.8%
Friends List With Benefits
While playing co-op, hug 3 different people on your friends list
5/20/2011
2:05:09 AM
Ultra Rare 1.4%
Still Alive
Complete Course 4 with neither you nor your co-op partner dying
5/19/2011
6:49:28 AM
Ultra Rare 1.4%
Party of Three
Find the hidden companion cube in co-op test chamber
5/17/2011
11:25:46 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
5/17/2011
11:12:16 PM
Ultra Rare 2.1%
Empty Gesture
Drop your co-op partner in goo while they are gesturing by removing the bridge under them
5/17/2011
11:02:55 PM
Ultra Rare 3.9%
Iron Grip
Never lose a cube in Chamber 6 of the Mass and Velocity co-op course
5/17/2011
10:54:31 PM
Ultra Rare 2.8%
Four Ring Circus
Enter 4 different portals without touching the ground in co-op
5/17/2011
6:42:41 PM
Ultra Rare 4.6%
Narbacular Drop
Place a portal under your co-op partner while they are gesturing
5/17/2011
9:39:52 AM
Very Rare 5.5%
Bridge Building
Complete all test chambers in the Hard-Light Surfaces co-op course
5/17/2011
9:38:42 AM
Rare 20.6%
Confidence Building
Complete all test chambers in the Mass and Velocity co-op course
5/17/2011
8:59:16 AM
Rare 31.6%
Team Building
Complete all test chambers in the Team Building co-op course
5/17/2011
8:46:51 AM
Rare 46.8%
Obstacle Building
Complete all test chambers in the Excursion Funnels co-op course
5/17/2011
8:26:03 AM
Rare 15.7%
Asking for Trouble
Taunt GLaDOS in front of a camera in each of the five co-op courses
5/17/2011
7:37:25 AM
Very Rare 6.0%