Throughout December, clusters of green and yellow symbols began to festoon Twitter feeds like festive decorations. The posts related to a simple, free online word game, Wordle, which has become a must-play trend in the past few weeks, with hundreds of thousands of people proudly sharing their daily score on social media. The game has the elegance of a daily newspaper puzzle – a five-minute conundrum that slots pleasingly into even the most harried routine: guess the five-letter word. You have six attempts. After each attempt the game marks your guess. Letters are marked green if they are present and correctly placed, yellow if they are present but incorrectly placed, and grey if they do not appear in the target word at all. As in the board games Battleship or Mastermind, you can use this meagre information to improve your next guess and close in on the target word. (Infuriatingly, the game offers no indication as to whether a letter appears more than once in the target word, a design choice that inspires howls of online anguish whenever, say, a “TRUSS” appears.) According to the New York Times, Wordle was created last year by a Brooklyn-based software engineer, Josh Wardle, as a gift for his partner. The game soon became a favourite among his wider family. Then its popularity steadily spread across the internet, from 90 players on 1 November to 300,000 on 2 January. The simplicity is the charm. One Wordle is released each day, and it’s the same one for everyone around the world. There are no advertisements, no niggling notifications begging you to return each morning, no novelty skins with which to alter the appearance of your letters, and no offer coupons in exchange for recommending the game to friends. With so much traffic, the incentive to profit from Wordle’s success is considerable. But the game’s rejection of the capitalistic systems that define so many video games today has a refreshing, innocent quality. Long may Wordle remain so pure.