I played KQ6 as a small kid who could barely speak English, and again ~10 years later as a grad student. The day I stumbled on the long ending and found myself in the Realm of the Dead still counts as one of the most mind-explodey things that ever happened to me.
I'm a native English speaker, but I was a young kid as well and so I remember learning a lot of the puns and wordplay in English much later on in life after first seeing them in that game. I'm sure another playthrough would reveal even more.
"Stick in the mud", "Wallflower", those sorts of thing.