Complete the following tasks to unlock the corresponding achievement. To view your achievements and stats in Steam, select "Community", then "My profile", then "View all my games", then the game and view stats.
| Achievement | How to unlock
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|---|
| Air Show | Perform 2 aerial gestures before touching the ground in co-op.
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| Asking for Trouble | Taunt GLaDOS in front of a camera in each of the five co-op courses.
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| Bridge Building | Complete all test chambers in the Hard-Light Surfaces co-op course.
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| Bridge Over Troubling Water | Complete the first Hard Light Bridge test.
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| Can't Touch This | Dance in front of a turret blocked by a hard light bridge in co-op.
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| Confidence Building | Complete all test chambers in the Mass and Velocity co-op course.
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| Door Prize | Examine all the vitrified test chamber doors.
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| Drop Box | Place a cube on a button without touching the cube.
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| Dual Pit Experiment | Do the same test twice.
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| Empty Gesture | Drop your co-op partner in goo while they are gesturing by removing the bridge under them.
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| Final Transmission | Find the hidden signal in one of the Rat Man's dens.
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| Four Ring Circus | Enter 4 different portals without touching the ground in co-op.
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| Friends List with Benefits | While playing co-op, hug 3 different people on your friends list.
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| Gesticul-8 | Perform all 8 gestures of your own volition in co-op.
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| Good listener | Take GLaDOS' escape advice.
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| High Five | Celebrate your cooperative calibration success.
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| Iron Grip | Never lose a cube in Chamber 6 of the Mass and Velocity co-op course.
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| Lunacy | That just happened.
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| Narbacular Drop | Place a portal under your co-op partner while they are gesturing.
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| No Hard Feelings | Save a turret from redemption.
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| Obstacle Building | Complete all test chambers in the Excursion Funnels co-op course.
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| Overclocker | Complete Test Chamber 10 in 70 seconds.
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| Party of Three | Find the hidden companion cube in co-op test chamber.
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| Pit Boss | Show that pit who's boss.
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| Portal Conservation Society | Complete Chamber 3 in the Hard-Light Surfaces co-op course using only 5 total portal placements.
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| Portrait of a Lady | Find a hidden portrait.
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| Preservation of Mass | Break the rules in Test Chamber 07.
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| Professor Portal | After completing co-op, complete Calibration Course online with a friend who hasn't played before.
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| Pturretdactyl | Use an Aerial Faith Plate to launch a turret.
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| Rock Portal Scissors | Win 3 co-op games of rock-paper-scissors in a row.
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| SaBOTour | Make a break for it.
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| Scanned Alone | Stand in a defective turret detector.
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| Schrodinger's Catch | Catch a blue-painted box before it touches the ground.
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| Ship Overboard | Discover the missing experiment.
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| Smash TV | Break 11 test chamber monitors.
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| Stalemate Associate | Press the button!.
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| Still Alive | Complete Course 4 with neither you nor your co-op partner dying.
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| Stranger Than Friction | Master the Propulsion Gel.
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| Tater Tote | Carry science forward.
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| Team Building | Complete all test chambers in the Team Building co-op course.
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| The Part Where He Kills You | This is that part.
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| Triple Crown | Solve 3 co-op chambers in the Mass and Velocity course in under 60 seconds each.
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| Tunnel of Funnel | Master the Excursion Funnel.
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| Vertically Unchallenged | Master the Repulsion Gel.
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| Wake Up Call | Survive the manual override.
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| White Out | Complete the first Conversion Gel test.
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| You Made Your Point | Refuse to solve the first test in Chapter 8.
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| You Monster | Reunite with GLaDOS.
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| You Saved Science | Complete all test chambers in all courses of co-op.
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