Companies large and small now screen applicants using tools like “Wasabi Waiter,” an online game that requires players to identify the emotions of diners in a sushi restaurant, serve them the meals that best correspond with their moods and keep up with a steady stream of demands to clear plates and seat new customers. The game’s creator, a startup called Knack, uses data recorded during game play to predict whether the applicant is likely to be successful in a given job.