My family used to play an add-a-letter game called “Ghost” on long car trips. One person says a letter, the next person adds one. The trick: There has to be a word that starts that way, and you lose if you end a word. Gets you searching those mental vaults for odd words that will stump people or at least not end on you. (Don’t go L-L in a three-person game unless you know another L-L word besides LLAMA, because it’ll end on you.) If you can’t think of any word that works, you can challenge. If you end a word, or lose a challenge, or just totally get flummoxed, you get one of the letters of G-H-O-S-T. First people to get all five letters loses, and play continues. Why this would be a cool computer game: Two people can play, so it’s possible to play against a computer. Besides, the program, theoretically, could play brilliantly, with access to its own dictionary and algorithms for finding and testing words and applying strategies. Of course, it could then be set for levels from “Safe” to “Terrifying,” by varying how much of the dictionary can be accessed. The name Ghost suggests colorful animated graphics. I think this game also has other names and variations (you can add letters to the end or the beginning) that might suggest other graphics or additional options. But last time I checked, I couldn’t find a workable version online. Wikipedia has a whole entry, but no link to any game.