Would it not also be correct to say: All the kids amuse themselves here? Meaning is the same and flows well in English.
"amuse themselves" suggests that they're not supervised. I'm imagining a situation like a fun park where the children are supervised, so your sentence wouldn't work for that, but "have fun" does.
I'm not sure it's fair to expect us to know what someone has imagined, particularly if starting from an assumption that supervision cannot be from a distance.
What is the difference between gamins and enfants? Is it like kids versus children?
Yes, pretty much. I could be wrong, but I believe that gamins is informal to enfants as kids is informal to children
You are correct.
Would "enjoy themselves" also be a valid translation?
Google Translate seems to think so.
What is the difference between 'enjoy themselves' and 'have fun'? Former not accepted.
Would this ever translate to "all the kids" instead of "all kids"?
Yes, it can be either.
Well, I put all of the kids have fun here. So this should be accepted.
I said the same and was marked incorrect. I reported
I put enjoying themselves. Why was it wrong??
How is "all children are having fun here" wrong?
Formal: enfant(e)s = children,
Informal: gamin(e)s = kids
Is "gamins" the plural of "fils"?
No, "gamins" means "kids". The plural of "le fils" is "les fils".
"All of the kids are having fun here" was not accepted.