Portal: Prelude Test Chamber 18 (Bonus)

This is the fifteenth Bonus map of the game. It is unlocked when the original Test Chamber 18 has been completed.

Hazards

 * Cube Hazard
 * Fire

Strategy
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Portals

 * To do

Steps

 * To do

Time
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 * To do

Award requirements
Please note the time challenge's awards are arranged in the reverse order.

Video strategies

 * To do