Not every jam has a story criteria, but this one does. In the past I've seen the story just be in the game description. People will write crazy little blurbs about how Timmy has to solve puzzles or aliens will eat his friends and family if he doesn't solve these games. Or the story is you're an office drone, and you'll get electrocuted if you don't do something fast enough and it's just a conveyor belt and stuff to sort. Story can also be conveyed through music, overall tone of the game, even the colors you choose. Tetris with muted browns and a dour song is much different from something with a cozy theme and happy, bubbly tetrris blocks.
Personally, I give pretty high marks for this one if people even try.