Portal Test Chamber 13 (Bonus)

This is the first Bonus map of the game. It is unlocked when the original Test Chamber 13 has been completed.

Hazards

 * High Energy Pellets
 * Cube Hazard

Strategy
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Portals

 * When retrieving the Weighted Storage Cube, try to use the same portal that you placed on the bottom.
 * Place a portal on the wall next to the Heavy Duty Super-Colliding Super Button in the next room.
 * Make a save before attempting to throw the Cube onto the other button.
 * Walk though the same portal on the wall near the button when reaching the exit.

Steps

 * When using floor portals, cancel your exit portal as soon as you pop out of it, by firing the same colour somewhere else. This is easy if you have a portal-friendly ceiling above, but can be tricky if you have to cast around for a surface mid-flight.
 * Place a portal right beside the button and another right in front of the chamberlock. Jump through and cancel the exit portal. With luck, you can do this in two steps.
 * Throw a portal onto the wall behind the cube and the other onto the floor in front of you. Crouch down to pick up the cube without taking any steps.  Don't reach through a wall or you will have to step back to get the cube clear of the sides.
 * Set the cube on the button then fire a portal through the walkway and the open door onto the ceiling above the higher button. Don't waste any steps while doing this.
 * Put your other portal on the floor in front of you then pick up the cube and drop it through. You're trying to get it on the platform, not the button.
 * Fire this same portal right under your feet so you drop through onto the button. If you're on top of the cube, start all over again - from your last quicksave, that is ;-)
 * Portal the cube onto the other button. If you can't see it, revert to an earlier save.
 * Place a portal on the floor or the nearby wall, and another on the floor near the exit.
 * Use floor-to-floor to get as close as possible to the Chamberlock.

Time
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 * Grab the Cube though the portal, don't waste time traveling into the portal to place it on the button.

Video strategies
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