There's nothing unusual about this sentence. In fact, it's very common. It's an impersonal passive construction which functions as a negative imperative. http://en.wikipedia.org/wiki/Impersonal_passive_voice#German
I agree that this sounds very German. But, one does not usually say things that way in English. The problem is, as always, how much latitude do we have in translating this? I wrote something like "No more games now, children." That was not appreciated by Duolingo, However, I think it gets the spirit of it and would actually be said to children here.
Another great resource. http://www.nthuleen.com/102/hausaufgaben/explpassiv.html (see "Aspects of the Passive Unique to German")
This sentence makes absolutely no sense to me. According to Duolingo, it translates literally into "Now will not more played, children".
How am I supposed to get "Now no more play, kids," OR "No more playing, children," out of such a thing? Wouldn't "Now no more play, kids," translate as "Nun kein mehr Spiel, Kinder"? And wouldn't "No more playing, children," translate as "Kein mehr spielend, Kinder"?
Is there something I'm completely missing here? Why is the German version of this phrase so clunky and long? Why is "wird nicht" used instead of "kein"? And why is "gespielt" used? Do people actually say it this way anywhere in any German-speaking countries?
I think the main issue is that Passiv is covered at the very end of the course, but there are some sentences with passive tenses here and there in the course.
You can't always translate german to english word-for-word (and vice versa). It is really difficult when Duolingo throws phrases at you like this without warning (especially without having learnt passive first), but this is how people will talk in Germany.
My translation of "Children, no more playing now" failed... And there went my last heart...