Hunter1942: Yeah there seems to be a few problems with that testing map.
Well now I'm working on a new map which will be as close to Portal as possible, but it will also include some original features like wallwalking or gravity flipping, spirit walking or... well the others should be surprises.
Here's a preview (it will take a few minutes to get approved by YouTube):
http://www.youtube.com/watch?v=ZcwXlwewzus
Note: All of the portals are controlled by the map, until you get to the mouse icon.
Until you get to the point where you can see the mouse icon you cannot create or control any portals.
After the mouse icon I press mouse1 to create the blue portal which will allow me to pass through to get to the red portal which was already placed by the map.
Man, I love Prey.
Edit: Oh, also the new version of the wrench disables falling damage.