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- Bronze: 16
- Silver: 8
- Gold: 5
3 Portal Strategy
- Proceed forward and shoot a blue portal onto the left upper wall as close to the portal immune wall as possible.
- Shoot an orange portal onto the lower level wall.
- Proceed through the orange portal and if you are quick enough you can take out or jump past the sentry. (Jumping backwards may help)
- Use the wallclimbing glitch with the sentry gun to make your way up to the platform with a cube on it.
- Throw the second sentry gun to the middle level.
- Place an orange portal on the back wall where you get the cube so that it is opposite the doorway.
- Take the cube with you and throw it on the second button.
- Carry a sentry gun over by the original blue portal and use it to deflect the power orb into the blue portal.
- Once you get it in the portal, quickly follow it, duck, and stand on the button so that it goes through the open door and is caught.
- Jump across the gap, drop down, and proceed to the exit.