Portal: Prelude Test Chamber 12 (Advanced)

This is the third advanced Test Chamber of the game. This version is unlocked when the original Test Chamber 12 has been completed. It as the extra challenge such as Goo facing the High Energy Pellet catcher, less white surfaces and the catcher now timed.

Hazards

 * High Energy Pellets
 * Goo
 * Cube Hazard