Gamma Energy visits the Aperture Science East facility, built after GLaDOS gained sentience. The goal was to create a facility where GLaDOS' research could be examined and tested without harm to employees or other people who actually... mattered, without her knowledge. Pick up a prototype Portal Device and try not to die.
This is the hardest chamber in the game, and was featured in the second trailer. I have yet to beat it myself without using the bullet time cheat. My brother has, though. He's better at this kind of stuff than I am.
I suspect this might be the kind of thing I could do in a couple of tries. I'm generally good at this kind of thing...
The map is kind of boring. Maybe add color correction or something to make it less bland.
And replace the nasty stuff with glowing blue coolant that stains the walls.