“An operative for an unnamed infiltrate-and-assassinate corporation has to invade an enemy facility and cripple their production of missiles and other weaponry.”
You find yourself in a cliff-side community village overrun by headcrabs.
There’s no where to hide or run, so the only way is forward.
Do what you do best (kill anything that gets in your way) and clear the village and hope for escape.
The Combine have acquired some sensitive data.
It’s your job to enter the Combine facility where it is being stored and erase it.
Expect heavy resistance, especially in attempting to escape.
In fact, the data could be a ploy to capture you!