flOw was originally developed as part of Jenova Chen's master's thesis for the Interactive Media Program at the University of Southern California's School of Cinematic Arts. His thesis was on the concept of dynamic difficulty adjustment, wherein a game adjusts its reactions to a player based on the past and present actions of that player. He illustrated his ideas with flOw. Chen allowed players to dive between planes at will, and provided the option of eating or not eating any creature. Players may decide to rush downwards, or to grow stronger before attacking powerful opponents.