GH is such a great game! Instead of turns for character actions, it has "panels" like comic books which is very cool. The system is kind of crunchy like AD&D where there's different tables for different types of combat, but if you like old-school crunch, it's fun. The random chargen is just as goofy as most superhero rpgs with random chargen and the "tone" of the writing was amusing.
I was into GH for a few months before discovering MSH
Fun Fact: GH authors Simon Burley and Peter Haines were under the impression that they'd be developing a Marvel RPG for Games Workshop. They were blindsided (and in Simon's words, "gutted") when GW announced that they didn't get the license, and they re-tooled the game into a generic supers game. GH had the misfortune of being released a week after Marvel Super Heroes and costing more to boot, neither of which did he game any favors commercially.
How do the update/retroclone Squadron UK compare?
I don't wish to be pedantic, but I'll mention that the currently available Squadron UK is actually the 2nd superhero RPG by Simon Burley to bear that name. The first one, from the early aughts, was more or less a straight clone of Golden Heroes. One Cease and Desist from Games Workshop later, Burley went back to the drawing board to come up with the currently available Squadron UK.
Been a while since I looked at the current Squadron UK, but off the top of my head...
-The "Frames" mechanic (an action economy of sorts) in SqUK is not limited to 4 per turn, as in Golden Heroes. It is also no longer guaranteed to be 4. Might be more, might be less. Gone also is the "back and forth" nature of combat, where one side might get some Frames, then the other side, then the original side. Now, it's winners of initiative act, followed by losers of initiative. The Initiative and Frames mechanic of Golden Heroes are standout feature for me, so this wasn't a change I welcomed.
-SqUK plays with the Attributes a bit. There are now 5 Attributes instead of four. The first 4 are physical, and the fifth, Psyche, is mental. Psyche is inversely proportional to the Physical Attributes. I didn't really care for this.
-SqUK has a formalized Skill system. GH had a skill system of sorts, though it was limited and heavily abstracted (which I didn't mind). Point to SqUK.
-SqUK no longer uses a binary pass/fail as in GH (though GH did have Crits). There are variable successes.
-Power Rolls (the "power points" mechanic of GH) can now be broken up into "half rolls" that can be spent on very minor/less advantageous versions of certain powers. For example, the "Shrink" power has a half-roll version, which is "smaller", i.e., the Character is permanently roughly half of average human size.
There are likely more differences, as I said, that's just off the dome. Overall, while I was glad to buy SqUK to throw some support Mr. Burley's way, I didn't like it as much as Golden Heroes, and ended up giving my copy away.
There's been at least two clones: Codename: Spandex and Squadron UK. I own one or both but couldn't tell you much about them.
Codename: Spandex is a largely faithful retro-clone, with only one difference that I can see from GH (the lack of "area Effect" gimmicks for Energy Attack). It is essentially GH with the serials filed off, and you can use it to run Golden Heroes material (not that there was much of that, sadly) with no conversion needed. It's probably the cheapest (free in PDF, at cost in print) and
easiest way to play Golden Heroes currently. The author, Gurbintroll AKA Blacky the Blackball, is currently working on a sequel/2nd edition of sorts, called HeroWorld. If it's like any of his other work, it should be great. But he is making a few changes that will move away from GH. De-emphasizing grid combat, for example. As with the initiative, this is a standout feature of GH for me, so I guess I'm gonna be a grognard about it. But one of the coolest things IMO about GH was that it did have a tactical tabletop aspect without being mired in crunch. Co-author Peter Haines was a big wargamer, and would go on to write for Warhammer.
Squadron UK is a sort of "spiritual successor" to Golden Heroes, designed to be sufficiently removed from the original to avoid litigation from Games Workshop. It has many things in common with Golden Heroes, alongside more modern design elements. It isn't a straight clone, however, and some elements are incompatible with GH.