10 Asking for TroubleTaunt GLaDOS in front of a camera in each of the five co-op courses
10 Bridge Over Troubling WaterComplete the first Hard Light Bridge test
10 Can't Touch ThisDance in front of a turret blocked by a hard light bridge in co-op
10 Confidence BuildingComplete all test chambers in the Mass and Velocity co-op course
10 No Hard FeelingsSave a turret from redemption
10 Portrait of a LadyFind a hidden portrait
10 SaBOTour 10Make a break for it
10 Ship Overboard 10Discover the missing experiment
10 Team BuildingComplete all test chambers in the Team Building co-op course
10 UndiscouragedComplete the first Thermal Discouragement Beam test
10 You Made Your PointRefuse to solve the first test in Chapter 8
100 You Saved ScienceComplete all test chambers in all courses of co-op
15 Bridge BuildingComplete all test chambers in the Hard-Light Surfaces co-op course
15 Dual Pit ExperimentDo the same test twice
15 Gesticul-8Perform all 8 gestures of your own volition in co-op
15 Obstacle BuildingComplete all test chambers in the Excursion Funnels co-op course
15 Stalemate AssociatePress the button!
15 Still AliveComplete Course 4 with neither you nor your co-op partner dying
15 Stranger Than FrictionMaster the Propulsion Gel
15 Tater ToteCarry science forward
15 Triple CrownSolve 3 co-op chambers in the Mass and Velocity course in under 60 seconds each
15 Tunnel of FunnelMaster the Excursion Funnel
15 Vertically UnchallengedMaster the Repulsion Gel
15 White OutComplete the first Conversion Gel test
20 Air ShowPerform 2 aerial gestures before touching the ground in co-op
20 Door PrizeExamine all the vitrified test chamber doors
20 Drop BoxPlace a cube on a button without touching the cube
20 Final TransmissionFind the hidden signal in one of the Rat Man's dens
20 Iron GripNever lose a cube in Chamber 6 of the Mass and Velocity co-op course
20 LunacyThat just happened
20 Portal Conservation SocietyComplete Chamber 3 in the Hard-Light Surfaces co-op course using only 5 total portal placements
20 Preservation of MassBreak the rules in Test Chamber 07
20 Rock Portal ScissorsWin 3 co-op games of rock-paper-scissors in a row
20 Schrodinger's CatchCatch a blue-painted box before it touches the ground
20 The Part Where He Kills YouThis is that part
25 Empty GestureDrop your co-op partner in goo while they are gesturing by removing the bridge under them
25 Four Ring CircusEnter 4 different portals without touching the ground in co-op
25 Narbacular DropPlace a portal under your co-op partner while they are gesturing
25 Party of ThreeFind the hidden companion cube in co-op test chamber
30 OverclockerComplete Test Chamber 10 in 70 seconds
30 Pit BossShow that pit who's boss
5 Good ListenerTake GLaDOS' escape advice
5 High FiveCelebrate your cooperative calibration success
5 PturretdactylUse an Aerial Faith Plate to launch a turret
5 Scanned AloneStand in a defective turret detector
5 Wake Up CallSurvive the manual override
5 You MonsterReunite with GLaDOS
50 Friends List With BenefitsWhile playing co-op, hug 3 different people on your friends list
75 Professor PortalAfter completing co-op, complete Calibration Course online with a friend who hasn’t played before
75 Smash TVBreak 11 test chamber monitors