I can't remember doing crosswords in english before, but at least here in Brazil, when the the question uses plural, it means the answer should be plural as wel

I can't remember doing crosswords in english before, but at least here in Brazil, when the the question uses plural, it means the answer should be plural as well, so "Bosses of the farm in Orwell's world" with 3 letters gave me a little pause, for example. Maybe it's nitpicking, but you might want to capture th "Esc" key (currently it outputs "ESC" when hit), and maybe either allow control+c to copy the question, or block it entirely (currently it outputs "C"). Maybe also punish the player for revealing the word, by not awarding points when it's used.