This is what you should have got with any retail HL CD key:
https://steamdb.info/sub/1/apps/
I can confirm it worked with HL1, CS Retail and Blue Shift keys.
https://steamdb.info/sub/1/apps/
I can confirm it worked with HL1, CS Retail and Blue Shift keys.
I only had Half Life, and Counter Strike was free when I started playing so I only got HL / CS. I didn't get the others free until HL2 came out...