The Dev Team Thinks of Everything/Animal Crossing


 * In the Game Cube version of Animal Crossing, your villagers complain if you send them gibberish letters because the game was designed to look for certain things... which means that you can still write gibberish so long as you use proper spacing and punctuation. However, writing a letter in French could result in the villager's return letter reading something along the lines of "Bonjour! Sorry, my French isn't very good..."
 * If you reset the game enough times, Mr. Resetti will force you to write a letter of apology. If the player doesn't write it exactly how he dictates, he'll force you to do it again. However, writing something like "Hell no" or "I hate you" will cause Mr. Resetti to freak out.