Full list of all 51 Portal 2 achievements. It takes around 20-25 hours to unlock all of the achievements in the base game on Windows.
The base game contains 50 achievements, and there is 1 DLC pack containing 1 achievements.
While playing co-op, hug 3 different people on your friends list
After completing co-op, complete Calibration Course online with a friend who hasn’t played before
Complete Course 4 with neither you nor your co-op partner dying
Solve 3 co-op chambers in the Mass and Velocity course in under 60 seconds each
Never lose a cube in Chamber 6 of the Mass and Velocity co-op course
Show that pit who's boss
Break 11 test chamber monitors
Taunt GLaDOS in front of a camera in each of the five co-op courses
Find the hidden companion cube in co-op test chamber
Complete Chamber 3 in the Hard-Light Surfaces co-op course using only 5 total portal placements
Drop your co-op partner in goo while they are gesturing by removing the bridge under them
Perform 2 aerial gestures before touching the ground in co-op
Enter 4 different portals without touching the ground in co-op
Complete Test Chamber 10 in 70 seconds
Discover the missing experiment
Examine all the vitrified test chamber doors
Catch a blue-painted box before it touches the ground
Save a turret from redemption
Break the rules in Test Chamber 07
Use an Aerial Faith Plate to launch a turret
Find the hidden signal in one of the Rat Man's dens
Place a cube on a button without touching the cube
Place a portal under your co-op partner while they are gesturing
Complete all test chambers in all courses of co-op
Complete all test chambers in the Excursion Funnels co-op course
Perform all 8 gestures of your own volition in co-op
Complete all test chambers in the Hard-Light Surfaces co-op course
Dance in front of a turret blocked by a hard light bridge in co-op
Win 3 co-op games of rock-paper-scissors in a row
Complete all test chambers in the Mass and Velocity co-op course
Complete all test chambers in the Team Building co-op course
Celebrate your cooperative calibration success
That just happened
This is that part
Master the Excursion Funnel
Do the same test twice
Refuse to solve the first test in Chapter 8
Complete the first Conversion Gel test
Master the Propulsion Gel
Find a hidden portrait
Carry science forward
Master the Repulsion Gel
Press the button!
Stand in a defective turret detector
Take GLaDOS' escape advice
Make a break for it
Complete the first Hard Light Bridge test
Complete the first Thermal Discouragement Beam test
Reunite with GLaDOS
Survive the manual override
Never lose a cube in Chamber 6 of the Mobility Gels co-op course