


Survive the manual override

Reunite with GLaDOS

Complete the first Thermal Discouragement Beam test

Celebrate your cooperative calibration success

Complete the first Hard Light Bridge test

Complete all test chambers in the Team Building co-op course

Make a break for it

Press the button!

Master the Repulsion Gel

Carry science forward

Complete all test chambers in the Mass and Velocity co-op course

Master the Propulsion Gel

Complete the first Conversion Gel test

Do the same test twice

Master the Excursion Funnel

Stand in a defective turret detector

This is that part

That just happened

Perform 2 aerial gestures before touching the ground in co-op

Complete all test chambers in the Hard-Light Surfaces co-op course

Save a turret from redemption

Place a cube on a button without touching the cube

Take GLaDOS' escape advice

Perform all 8 gestures of your own volition in co-op

Complete all test chambers in the Excursion Funnels co-op course

Break the rules in Test Chamber 07

Complete all test chambers in all courses of co-op

Find a hidden portrait

Discover the missing experiment

Win 3 co-op games of rock-paper-scissors in a row

Dance in front of a turret blocked by a hard light bridge in co-op

Taunt GLaDOS in front of a camera in each of the five co-op courses

Use an Aerial Faith Plate to launch a turret

Show that pit who's boss

Examine all the vitrified test chamber doors

Catch a blue-painted box before it touches the ground

Enter 4 different portals without touching the ground in co-op

Refuse to solve the first test in Chapter 8

After completing co-op, complete Calibration Course online with a friend who hasn’t played before

Place a portal under your co-op partner while they are gesturing

Find the hidden signal in one of the Rat Man's dens

Drop your co-op partner in goo while they are gesturing by removing the bridge under them

While playing co-op, hug 3 different people on your friends list

Complete Test Chamber 10 in 70 seconds

Break 11 test chamber monitors

Never lose a cube in Chamber 6 of the Mass and Velocity co-op course

Find the hidden companion cube in co-op test chamber

Solve 3 co-op chambers in the Mass and Velocity course in under 60 seconds each

Complete Chamber 3 in the Hard-Light Surfaces co-op course using only 5 total portal placements

Never lose a cube in Chamber 6 of the Mobility Gels co-op course

Complete Course 4 with neither you nor your co-op partner dying