The current study explores the relationship between perceived cognitive and physical demands of a simple video game, and the balance of reward and effort that results in flow states during gameplay. Cognitive demands and both exertion-based and controller-based physical demands were perceived as lowest in situations where reward was high and effort was low (boredom), moderate when reward and effort were balanced (flow), and highest when the reward was low and effort was high (frustration). Surprisingly, player response times to a secondary task showed the greatest improvement when playing the frustrating video game condition. We interpret this latter finding as evidence of an observed task-switching effect: players initially tried to master the game's over-challenging primary task before giving up and, instead, diverted attention toward a secondary in-game task that required less effort and thus, gave greater attentional rewards to the player. The implications of this cognitive offloading are discussed.