This test chamber is the eleventh bonus level of the game. It is taken from Portal: The Flash Version MapPack. The challenges of this level are unlocked when the test chamber is completed once.
Once you fell onto the flooring under the crusher, portal over the Goo. Proceed to the other door.
Portal ono the one-part portalable walls by putting one portal onto the floor and the other one onto the wall that I've mentioned.
Shoot a portal trough the square hole and go trough an another portal that you will place on the floor, after falling down on the portalable flooring.
While the Crusher is falling down, shoot two portals - one that is in your reach and one really high on the portalable wall. Look trough the high portal and shoot a portal trough the square hole onto the opposite portalable wall while falling down onto the floor, after that just put an another portal on the floor to go through.
After proceeding through the door, find a big piston.
When the piston pulls back, shoot a portal onto the 2-tile portalable wall and wait for it to pull back again and shoot an another portal on to a portalable surface at the doorway. Repeat the same thing, but every time you put a portal on to the two tiles, pull abck and go back to the start.
At the end of the piston sequence, shoot a portal through the square hole while the piston is pulling back and proceed to the Chamberlock.
