The Combine Soldiers wear the gas masks to allow them to breathe in different atmospheres - they can be posted off-world.
With the Combine, conquered races are forcefully integrated into the Combine army, lobotomised and turned into stalkers or killed depending how useful they are the the...
I considered the crane and other evidence in favour of draining but the highway itself seems like it was built when the water was at the current level and the highway seems as if it was man-made not built by the combine.
I suppose tides could account for the discrepancy (if there are no tides...
One thing I don't get - on the coast levels the water seems to be at a normal level, surely if the combine were draining large quantities of it it would be lower?
You can throw stuff at civilians and they never hit you back.
The pick-up-the-can cop at the start lets you past if you put it in... as opposed to smacking you anyway (I get the feeling he was just looking for a reason to smack you).
Gordon doesn't ask for a suit which isn't flurescent orange.
Build the tower to the side balcony like The Thing said, you can use the crates to make a 1-2-3 step thing (although I'm missing one when I replay it now but just use a barrel instead), take 2 turrets up to the balcony and set them up, then get the third one and jump up the stack while facing up...
The Thing is right.
The Combine launch headcrabs into an area, where they will zombify some people then kill the rest. Then soldiers just come in and kill the zombies (easier than killing resistance members)
The chemical agent introduced to the water supply makes people suffer long-term memory loss, so if Breen makes them seem like good guys people will forget the past and assume that the combine have improved the conditions of living from something worse than what it is currently.
Reckon Dog's Ball counts as an enemy (since it's a deactivated rollermine), and the invisible walls stop enemies from getting through - therefore Dog's Ball too?
Hit the button on the cabinet, grab the turrets with the gravity gun and place them back-to-back and the door you came through (facing to the sides, of course). Be wary of manhacks and one soldier who shoots down from the balcony (look at the window to see him).