Golden Heroes was first published in 1981 on a small press, hobbyist basis – a labour of love by Simon Burley and Peter Haines, its authors. Come 1984, it ended up getting a revamp and release by Games Workshop: they’d bought the rights to the system as part of a plan to bid for the Marvel Comics RPG licence, and then when their bid fell through (losing to TSR, whose Marvel Super Heroes took a very different approach) Games Workshop decided to not bother applying the Marvel-flavoured reskin and put out Golden Heroes as it stood, in a boxed set which was the basis for a short-lived product line which retains a strong fan following to this day.
In fact, that fan following is strong enough that even decades after the game went out of print, both the fan community and one of its original designers have kept the flame burning. Codename: Spandex is a full-blown retroclone of Golden Heroes, whilst Simon Burley has kept his hand in the RPG design game (focusing mainly on the superhero genre) and produced Squadron UK, a spiritual successor to the game based on many of the same principles. If you want the Games Workshop version, the original boxed set still pops up on EBay, or if you want to go a bit thriftier with it you can find the actual rulebooks (the only components you strictly need) separately.