I should hope that the friendly-faced big brother fascism government is public domain by this point.
Calling it a homage also kinda undersells the absolutely spectacular writing of it all.
HL1 was a homage to all things "SCIENCE EXPERIMENT GONE WRONG"/"OH NOES, ALIENS" as well as Quake, given that it built off the Quake engine and nicked a good deal of the weaponry.