Brilliant idea @carisomalley! I love the idea of the white squares, that solves one problem.
@harald - the odd thing about our setup this summer is that we're not doing a kids version, just adults & teens - so I wanted to have it more complicated... can tweak the text to fit our needs only so much because the other problem I've found is that long words are broken up across lines. So, unless I think of a workaround for that, we'll have to keep our codes breakers short.
It does work nicely on the user interface, where someone can choose easy, medium, or difficult.