I ended up comparing the intros, in the rail cart bit last night. They are quite different surprisingly. (Hrm, I'm developing weird habits as a sleep deprived parent).
I'm on a good pc, 3070, Ryzen 3600.
I never really played this back in the day. Though I did buy half life 2 around release and nearly completed it but this was before steam did cloud saves so I don't have my save file anymore.
I see I can buy the full collection for a bout 4 pounds. Opposing force looks interesting.
I really shouldn't be buying games I don't have time to play!