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Teaching you the correct way to play HL2.
To get a copy of the old engine version of Half Life 2, go to this page: https://sourceruns.org/source/downloads/
You are looking for the one that says HL2 Old Engine Unpack. It runs as a source mod.
Music at the start of the vid is Hard Fought, my favourite HL2 music track: https://www.youtube.com/watch?v=ImDxuy371zs