Something needs to be fixed as this is an annoying aspect of Gordon’s movement. Minor, but annoying.
Tested on both game-pad and keys, moving either left or right will cause Gordon’s head/camera to tilt to the left or right as he is moving in that respected direction. This is either a puzzling design choice or something neglected during development. Perhaps it’s an issue with my version, although it seems to be the same subtle issue with every YouTube play-through I can find.
Reflecting, it does seem to add a bit more realism to the walking movements, but it just looks and feels odd as no current Source games do this. Almost looks like Gordon is drunk, actually.
I don’t remember if the original game was like this, but certainly HL2 does not and shouldn’t that be what this game feels like?
One more thing to be corrected, the Keys interface does not remember to display game-pad inputs after they have been applied. The controls still work fine, but going in to edit the keys again produces blank spaces where the names of the buttons used to be.