Portal 2 achievements

23.94%

Portrait of a Lady

Find a hidden portrait

34.37%

You Saved Science

Complete all test chambers in all courses of co-op

39.56%

Obstacle Building

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

40.50%

Preservation of Mass

Break the rules in Test Chamber 07

40.66%

Gesticul-8

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

43.71%

Drop Box

Place a cube on a button without touching the cube

45.13%

Good Listener

Take GLaDOS' escape advice

45.72%

No Hard Feelings

Save a turret from redemption

45.95%

Bridge Building

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

47.26%

Air Show

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

51.77%

Scanned Alone

Stand in a defective turret detector

54.66%

Lunacy

That just happened