Languages in which "gameplay" or an equivalent exists:
English
French
Spanish
Languages in which "gameplay" or an equivalent doesn't exist:
Japanese
Greek
I also don't think it exists in French, though I do think they have borrowed the English word. It's been a long time since I read a French magazine, however (and back then I wasn't paying attention to the issue since I was using the word myself), so I'll let a French person enlighten us.
When the list is done I'll post it on the frontpage. The idea is to show that millions of people from across the world are doing perfectly fine discussing games without this word or an equivalent.