The levels in this mode use the game's core puzzle/gameplay system and feature challenges with very limited solutions. The purpose is not to give the player the freedom to play around with countless, emergent, and divergent possibilities while exploring the results of their choices. Rather, the purpose of the challenge in a puzzle mode is to limit the player in such a way to test their knowledge of the puzzle engine and their logical strategies. Puzzle mode levels typically deemphasize real time, action based skills (timing, reflex) in order to completely test the player's knowledge skills (logic, deduction, analyze). This means that many puzzle modes are turn/move based. Like a clever joke or plot twist, the challenge and engagement comes from learning the solution/punch line. Usually, once a puzzle mode level is completed, there's little challenge and therefore incentive for players to replay it. This is known as the "spoiler effect"