- Bronze: 10
- Silver: 6
- Gold: 4
4 Portal Strategy
This is very difficult no matter how you do it and will require multiple attempts.
- Proceed forward to the small step. Jump up a little bit and shoot a blue portal in the center of the floor near the raised block with a sentry on it.
- Shoot an orange portal on the floor near yourself and fall through.
- Facing the entrance, shoot an orange portal high up on the ceiling by the cube dispenser button and proceed through.
- Push the button until the companion ball bounces down to the first level.
- Bring the ball back to the top level by the button, crouch down, and try to throw it into the long tunnel with a sentry inside. Eventually you should be able to knock the sentry over this way. Both this and the next step will take many tries to accomplish.
- By crouching and falling very carefully it is possible to land in the long tunnel.
- Once in the long tunnel it is very simple to place the ball on the button, shoot an orange portal behind the glass wall on the opposite side of the room, and fall through to the exit.
Alternately, but also quite difficult, one may shoot an orange portal high on the wall behind the glass then fall from the high area and launch into the long tunnel. This method is likely to require reloading when failed though, so using the other may be faster.