Secret special unit called the Combine Soldiers are developing a secret gun. About this weapon, however, that no one has really seen. Your task is to find the factory where the new weapon developed, destroy all plans. I dont know what to do in the room with the toxic gas, i used noclip When you eliminate all the soldiers and helicopters, the game end. There is a bug at the beginning of the game: G-man would have to kill the soldier, but it does not. You have to put the game in normal or easy, because in hard mode G-man does not kill the soldier. Also check my uploaded maps.
Some mod makers didn't realize the apache's condition never triggers anything. That's why this mod never properly ends even though it's set to show a black screen when the chopper gets destroyed.
Another mod I remember on top of my hand that had the same issue is Solo Operations.