So, I have taken interest in the whole concept of speedrunning, and I have found it quite amusing. I have seen some runs that focus on completing a game in a certain way, instead of just plain completing it quickly, such as the No Suit Run, or the Crowbar Run, and I thought of the idea of completing Half-Life with the command “sv_friction 0”.
Good idea, but in my opinion, a negative air accelerate run would be more entertaining to watch (sv_airaccelerate -10).
I guess with negative air accelerate it might end up in a no jump fashion or in an ADing fest. No friction sounds really interesting tbh.
9mmhandgun run
no gravity run
trigger_changelevel-delay run, using every possible shortcut (using impulse 101 where the weapons are lost)
YaLTeR made a testrun of hazard course with -10 airaccelerate. Would be cool to have of the full game.
There it is if someone is interested; it is more like a PoC really.
http://www.youtube.com/watch?v=DonCa0KYbPI
I wanted to do a 9mmhandgun only run earlier, since you can get it before crowbar. Anyway, I stopped after c1a0c because I realised that you have to get the crowbar in Residue Processing 
No friction run would be the same bunnyhopping, except sliding on the places where you must walk, but because of the limited airaccelerate you’ll have to slow down at turns anyway.
The reason to bunnyhop is because there is no friction in the air. Without friction on the ground it’s faster to slide than bunnyhop. I think that was OPs main intention about it.
I have expeirimented a little bit with zero friction in HL:S. It is quite fun when you are in an open area, but HL1 doesn’t have too much of that. I was thinking I would do my own speedrun of the game, but I am not very fond of health sacrafices, which speedruns are all about.
Yeah I get it. You’d still have to Bunnyhop in order to gain speed 
I insist. Without friction on the ground it’s faster to slide than bunnyhop. Try it.
No, you wouldn’t have to bunnyhop. Strafing can make you gain an insane boost. You can try this in long hallways. You will have to get used to looking not-forward, though. I tried doing this, and I slid right over the catwalk that the bullsquid falls on in “Unforseen Consequences”.
Frictionless Bump
PS: Just went frictionless all the way to the the cliff in surface tension. Rage Quit at that point.
I think this should be made into a run, its got a lot of potential