Neuroscientists tap gamers to learn how people problem-solve Fans of Candy Crush Saga, Flow Free or Minesweeper should check out a challenging new mobile game app, hexxed, that will stretch your brain as it helps brain researchers understand human strategic thinking and perhaps improve the reasoning of artificial intelligence. Those who download hexxed will confront a game more challenging than most phone-based games, which can be played mindlessly while killing time or watching TV. Those playing hexxed must learn how to succeed with almost no instructions — they have to figure out the rules on the fly. “I really wanted to avoid biasing the player as much as possible, so in a sense, it is at odds with one of the basic principles of game design: Use storylines to orient the player,” Agarwal said.