The game is overall good, and a gorgeous recreation of a game more than a decade and a half long, yet I feel it lack that clarity and subconsious acrhitectural hint Valve explores in its games. I even feel that were they remaking the original game, they would make many parts even better than they were in HL1
bm_c2a5a was especially egregious in that: that one level in “Surface tension” where you jump off the bridge into water to escape a helicopter machinegunning you to death.
I played HL:Source, so I vaguely remembered there is some ladder, and a trigger/button/valve to open the underwater grates (you can get to the other side of the dam trough the pipes).
It took me HALF AN HOUR dying over and over again to find that ladder on one of the towers in the water. See, when your have your hands full with staying out of harm (the machinegun can, surprisingly, get you tens on feet underwater even at flat angles), it is not that easy to find a sand-brown ladder on a sand-brown wall through underwater blurring.
There are other examples - like the ladders in the rocket shaft (bm_c2a2b), which don’t attract attention due to bright (and useless) gates and posters hanging around.
Residue processing: at the water purifying facility bm_c2a4b THAT opaque substance doesn’t look like something one can dive into (moreover, it resembles radioactive waste from HL2). I would really want it to be somewhat transparent.
In the next, production line level (c2a4c) the layout was damn confusing even in the original… Maybe make it slightly less so by adding extra ladders? It is not that hard once you did it. However, the moment you fall of the belt, you need to go back by untrivial spaghetti of corridors, so you instantly lose the feeling of what room you are in… Or, probably, you can force stronger visual contrast (color, texture, environment) between the different rooms, so once you get into the one with the production line, you know instantly which part it is.
The first teleporter system (c3a2g, vertical shaft)… The area is shiny, bloomy and all, which looks pretty but harder to comprehend. To remind, you have a vertical shaft with several sets of rotating platforms and several teleporter orbs in the centre. It took me long to actually get it that there are THREE of them, i.e. you get into different areas depending on what side you enter the central part from.
It shines so intensely that you can hardly see what’s inside the central column - and to get the system, you MUST know that there are three orbs around, not just one central teleporter beam. I would suggest making the glow less intense, or inserting a darkened glass tube around the ray, to make glowing orbs stand against the central glow.