Hero or Foe puts you in an underwater arena where both friendly and hostile creatures roam. You must decide who to catch and who to avoid. Friendly fish will grant you extra rewards, while hostile ones may reduce your progress. The challenge lies in catching the right fish while dodging the dangerous ones. Players are ranked by their ability to identify and catch friendly fish while avoiding harm. High-ranking players will receive heroic rewards, including permanent abilities that boost your octopus's decision-making and catching speed.