Ok, so sometimes "nem van" is "nincs" and sometimes it's just "nem" omitting "van"...anyone who could explain, please ? :)
Nincs is "there is no.." or "doesn't exist". Nem is just simply no. Nincs játék = there is no game (or toy).
The positive version of this sentence would not have van, either!
According to Wiktionary, "nincs" means "there is no/not"
'This is not a toy'..... not accepted?
"toy" would be "játékszer".
As far as I know, játék can mean "toy" as well. I would certainly use it instead of játékszer in that meaning too. (Though in that case the sentence would be more natural with the indefinite article included).
My great grandmother said this to me a lot when i was small :-)
You think this is a game, child? Ez nem játék!
Definitely this course it isn't!
This is not a game - ez nem egy játék