Quiet Rehabilitation brings a different story of Gordon Freeman being taken prisoner directly to Nova Prospekt. In this alternate route, without meeting Barney, he must find a way to escape from this old facility heavily guarded by Combine forces and surrounded by unusual creatures.
A very short teaser when the player manages to get out of the underground area of the prison, showing bits of Nova Prospekt in daylight as an aftermath.
You've really managed to nail the feeling of Nova Prospekt here; nicely done!