To unlock the "Thinker" trophy in "The Bridge", you must complete all 6 puzzles in Chapter I.
To get to chapter I waggle LT and RT until the Professor wakes up. Then walk and slide right until you reach a house and enter the door with an "I" on it.
Note: Light pulls of the LT and RT triggers make slow and slight movements. Heavy pulls of the triggers make quick & strong movements.Chapter I-I: The Loft
Hold RT to rotate the level 270 degrees (i.e. three quarters of a full circle). The Professor lands on the pillar. Walk left to drop through the centre part of the pillar to the next one. Walk left and rotate left with LT to reach the door.Chapter I-II: The Library
LT 180 degrees so the book in the middle slides to the original ceiling. Walk left and drop off the edge. RT 180 degrees to return the book to its original position. Walk to the door. Rotate this level very slowly without making significant noise (no controller vibrations) to unlock:
The Whisperer trophy in The Bridge worth 33 pointsComplete The Library being no louder than a whisper.Chapter I-III: The Menace
If the Menace (the ball) touches you at any point, you die. Walk right and you will slide into the "fish" section of the level. Strong RT hold to send the Menace to the door. Walk the Professor right with a light RT hold to make him carefully fall to the bird section. Strong RT hold to get the Menace to the fish section. Walk the Professor right with a light RT hold to make him fall to the door.Chapter I-IV: The Courtyard
Walk right and fall off the edge to the level with the Menace on a chain. Pull LT to head to the key while the Menace falls away. Pull RT to reach the door.
(There's a Wisp in this level that you will need for the Collector
trophy. Rewind for a full minute at the beginning of the level until the Professor is flung high in the air, and a Wisp appears in mid-air. Use LT and RT to position the Professor correctly on his long fall back so that he connects with the Wisp. You can rewind as much as you like at this point to position the fall correctly.)Chapter I-V: The Spiral
Follow the keys. Pull RT and the upper-right key will eventually wind its way all the way around to where the Professor can pick it up. Pull LT to start moving the other key but eventually you'll see it's about to slide right out of the maze and out of the level. Once it's on this side of the maze Pull RT to slow it down as much as possible. You want to guide the key around the outer edge of the platform here until it falls into the same spiral that the first key was in. Once you get it there, just pull RT to eventually bring it around to the Professor and open the door.Chapter I-VI: The Nook
Pull LT 180 degrees so that the level is upside down. Pull a little more on LT gradually to get the Menace to the left. Walk the Professor left to where the Menace started. Pull RT to flip the level 180 degrees again back to the starting position. Fall down to the door.
Once you have completed all of the puzzles in this chapter the trophy will unlock. Here's a video by ArsenalRobert
, full credit to him for the video.