On Chapter 2 "Test Chamber 7", keep track of the Companion Cube in this chamber. You may return to get it after using it to depress the button at the end of the level. Ignore GLadOS's comments and carry the cube through the broken "Emancipation Grill" at the end of the chamber and the achievement is yours.
On Chapter 9, after Wheatley's surprise, portal away from the platform just as Wheatley sends arms to crush you. Instead of running, stay nearby and Wheatly will beg you to come back. Stand at the edge of the pit overlooking his trap until he asks you to just jump in the pit. Jump in and the achievement is yours.
Find the turret inside a ventilation grate just past the elevator in Test Chamber 16 and jump over it to get the Refraction Cube. Then, use the laser to destroy that turret to open the grate. Enter to find four turrets singing a song.
On Chapter 2 "Test Chamber 6", get the radio that appears in a clump of garbage into a window above the chamber after you hit a button. Make your way back through the level and place a portal on the pad across from the window, then use the launchers to get through the portal and into the room past the window, with radio in hand. Take the radio up to the wall and the achievement is yours.
On Chapter 5 "The Escape", reach the conveyor belts carrying droids to the incinerator. Use a portal to get onto the conveyor belt and walk on the belt until a droid with a working laser beam appears. Pick it up and the achievement is yours.
On Chapter 6 "The Fall", reach the 1958 "28" room. There is a cube that's trapped in a glass box and Blue Gel streaming out of a pipe in one corner in this room. Save the game, then shoot a portal under the Gel and over the crate to coat the cube. The cube will bounce until it breaks the glass and eventually break out of the glass. Catch this cube before it touches the ground and the achievement is yours.. Note: Stand between the entrance and the gel spout.
On Chapter 6 "The Fall", reach the 1971-era test facility and Cave will begin talking about testing on hobos. Below one of the test spheres and a giant Aperture logo is a room marked "CONTROL ROOM" with yellow letters. Use a portal to get high above the Control Room. Enter the small office. Enter the door behind the cabinet and follow the hidden hallway to a dock. At the end of the walkway, near the docks, is a orange life preserver marked "BOREALIS". Examine it and the achievement is yours.. Note: This is a reference to the Aperture ship "Borealis" that is seen at the end of Half Life 2: Episode 2.
Add the "-console" command line parameter to end of the "Target" field in the "Shortcut" properties that are used to launch the game, then start the game and the console window will appear at the starting menu. Enter sv_cheats 1 to enable cheat mode, then active one of the following functions by entering the corresponding codes at the console window. Note: You can also press ~ during game play to open and close the console window.
Changes speed of game, 0.1 = 10% of original game speed, 2 = twice the original game speed
host_timescale # (default=1)
Changes the acceleration of the speed gel
sv_speed_paint_acceleration (default = 500.0f)
Changes the maximum speed obtainable from speed gel
sv_speed_paint_max (default = 800.0f)
Changes the minimum speed (in seconds) in which the portal gun shoots when you hold click. (Affected by portalgun_fire_delay)
When going for the "Ship Overboard" achievement, there are three metal doors in the hallway once you enter the door behind the filing cabinet . If you activate the doors, Cave Johnson talks about the tests. Activate all three doors and the achievement is yours.