Semantris

 On the eleventh day of Antonym Christmas, the Internet gave to me: 

a stupidly addictive game

When new word game apps, like Wordle and Spelling Bee, came out, I was so grateful for their once-a-day rationing. You see, I used to have an addiction to Tetris, and I would go the same way if there had been unlimited Spelling Bee. (There probably is—please don't point me toward it.)

But then Google research, in a clever way to get me hooked on an AI bot, released its Semantris games, which combines word association (antonyms are very useful here) with Tetris.  (I play the untimed Block version.)  I have lost my Christmas holidays to it. You have been warned.

Here's the link to play, if you dare.