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- Bronze: 8
- Silver: 5
- Gold: 2
2 Portal Strategy
- Standing as far from the cube killing button as possible while still being able to press it, jump very quickly towards the door immediately after pushing the button. Jumping backwards may help, and if you are quick enough you will be able to get through the door without using any portals.
- Ride the elevator to the next area.
- Push the next cube killing button while standing directly under the dispenser.
- Facing upwards, you will be able to grab the cube as it comes down which will keep the door open and allow two or more cubes to fall instead of just one.
- With two cubes stacked in the corner, shoot a blue portal through the top hole and an orange on the side wall.
- Bring a cube through the blue portal to set on the button.
- Proceed back through the orange portal to the exit.
Alternately, it is also possible to complete by stacking only one cube in the corner, but using two cubes makes it a little easier.