A great, great story, really well told. Kudos. :-)
I myself, after over 30 years of gaming, consider Half-Life the best video game ever. Even a step better than HL2 and Deus Ex. What you did was really amazing.
Regarding your role being unnoticed, apart from what you mentioned, I think some roles are just not known or understood by the wide public - and they will never be. Common people see the success story, the great product, and have NO idea of what lies underneath it.
E.g. I'm a graphic designer: if I book I design becomes famous, people will talk about the writer and the story and the characters, and nobody will think about the design; design is "transparent" to common people, and so usually is also marketing, engineering, etc. Look at Apple: everybody knows Steve Jobs, but only the nerds know who designed the Macintosh. :-)