Portal/Chamber 14

Chamber 14 involves more momentum puzzles, as well as the puzzle of how to bring an energy pellet a long distance, around several corners.

The first challenge is to get hold of a cube to put on a button so that a door can be opened. This may sound straightforward, but the cube is on top of an unclimbable raised platform.

Getting the cube
Turn to the left and walk forward. As you do so, stairs will rise up, allowing you to simply walk to the pellet receiver. The cube is on your left. This is a momentum puzzle, as indicated by the fact that the stairs to the pellet receiver area retract once you're up there. Place the first portal high on the wall to the right of the raised area. Place another portal at the bottom of the pit formed when the stairs retracted, and fall into it. You should fly onto the raised platform.

Once you're on top of the raised area, you can pick up the cube and take it down to the button. As soon as the cube is off the raised platform, the stairs will permanently rise up again. Put the cube on the button and open the door.

Getting the pellet
The door leads around a corridor to a room filled with sludge and some platforms which periodically go up and down into the sludge. On the other side of the room is a small antechamber with a pellet launcher; either use the platforms or a portal to get to the room.

Once in the room, place a blue portal over the scorch mark on the wall, letting the pellet through. Now jump across the platforms and continue to the pellet receiver.

At the pellet receiver, simply place an orange portal on the red spot above it – letting a pellet into it – and ride the lift below to the chamberlock.

Alternatively, before leaving the first room, fire a portal to the spot above the pellet receiver. Then walk across the platforms with the sludge and fire the alternate portal at the scorch mark.

"Very, very good. A complimentary victory lift has been activated in the main chamber."

- GLaDOS

Advanced
In the advanced chamber, a potential shortcut of flinging yourself onto the exit platform is prevented because the floor was made portal-proof. The box is also harder to reach due to more portal-proof surfaces, and the three platforms in the goo room are removed.

To reach the cube, you need to shoot a portal down the staircase and one next to the box section. Jump down, and you can maneuver yourself onto the box section. Place it as normal on the button.

To reach the pellet, you need to portal across the water area. The place a blue portal on the scorch mark, and an orange portal back on the other side. Avoiding the pellet, walk all the way back to the main area, and place an orange portal above the pellet receiver. The exit lift will now lower.

Portals

 * Bronze at 6 portals
 * 1) Blue portal on wall to fling towards cube.
 * 2) Orange portal at bottom of retracted stairs. Fling and grab the cube, placing it on the button.
 * 3) Blue portal across water gap.
 * 4) Orange portal in accessible location. Travel into pellet room.
 * 5) Blue portal on scorch mark. Travel by jumping or existing portals to main area.
 * 6) Orange portal above pellet receiver.


 * Silver at 4 portals
 * 1) Blue portal on wall to fling towards cube.
 * 2) Orange portal at bottom of retracted stairs. Fling and grab the cube, placing it on the button. Jump on platforms to cross the goo.
 * 3) Blue portal on scorch mark. Jump back across to the main area.
 * 4) Orange portal above pellet receiver.


 * Gold at 2 portals
 * 1) Blue portal on ground in front of the lift, as close as possible.
 * 2) Orange portal at bottom of retracted stairs. Jump in, and control your flight to land on the raised lift.

Steps
You can achieve bronze by using the pellet, but to get gold, you will have to use the shortcut route described in the 2-portal solution. You will use many more than two portals to do it, but that is the type of shortcut you should take.
 * Bronze at 55 steps
 * Silver at 20 steps
 * Gold at 10 steps

Time
Staircasing gets you within 20 seconds, but going for least steps is possible within 10.

Awards at 50, 20, 10.