The common refrain is that video games are played for their challenge. For a long time feeling the sense of accomplishment from beating a game is why many players would say that they played video games and that creating a challenge for the player is a game’s purpose. This is, of course, not true, and challenge should only be included when it is useful for the game’s own goals and what experience that it wishes to craft. Adventure games, for example, don’t test the reflexes or a player’s management skills, as other genres that might typically be seen as challenging do. What is challenge in an adventure game?
Typically, it is arriving at that “aha” moment. Reaching that moment requires the act of applying non-traditional keys to non-traditional doors. It may be attempting to apply an item to the environment or trying to give another character an item and receiving something in return. The challenge is in solving logic puzzles, most of which come in the form of environmental riddles. Traditionally, the problem with this approach to challenge has been in trying to balance these puzzles, both in terms of making them difficult enough to deliver that “aha” moment and also in not creating puzzles that are absurd enough to stall the player or make the player quit the game entirely.