İ think scientist so angry

Half-Life: Opposing Force - "We Are Pulling Out" (CH3) - tram ride

Half-Life: Opposing Force - Welcome To Black Mesa (CH2) - Tram

Half-Life: Opposing Force - Welcome To Black Mesa (CH2) - Sewer

.

Galvanized steel #1

Half-Life: Opposing Force - Welcome To Black Mesa (CH2) - Radio

Half-Life: Opposing Force - Welcome To Black Mesa (CH2) - Transit System Tunnel

bro WTF

Half-Life: Opposing Force - Welcome To Black Mesa (CH2) - Crash Site