What if Cave Johnson's multiverse theory was right? In which one includes Aperture buying out Black Mesa, and canceling the Anomalous Materials Research. You, as Gordon Freeman run through Blaperture Mesa and the new testing facility in Sector C. Testing goes horribly wrong however and Gordon gets sent deep underground to the abandoned Anomalous Materials labs, and re-activates the Anti Mass Spectrometer. Causing the resonance cascade, and going through the decaying Blaperture Mesa Facilities to make it to Aperture, where a rouge AI protects a multiverse portal that could lead Gordon home.
The ruins of the abandoned Sector C laboratories, with a crashed Blaperture elevator.
*Updated February 12th 2022*
thats the old BLACK MESA
Do you plan on updating the world brushes to fit with the style of Source engine games? Seeing the simple brushes from Half-Life really clashes with the style of Portal.