Added a new game to FB and it's flooding your friend's News Feed with "__ plays this; you should, too!" messages? No need to let a silly game spam your friends and family.

Go into Settings (upper-right)...Apps (left margin). You may find some old apps that you can remove entirely. But, if you click the little pencil (see pic), you can edit its permissions and change "Public" to "Only Me". You might also look at some of the non-Required permissions and see about limiting that app's scope.

Lastly, go a little further down the Apps page and look at "Apps Used By Others". Lots of stuff in there that you probably want unchecked (I have it all unchecked).