I've seen this discussion come up in a few threads before, and I think it's high time we had a thread dedicated to discussing it.
Usually, this comes up in the context of games like Dear Esther or The Stanley Parable, where someone calls those "walking simulators" or "not a game", and another person gets uppity about that. Let me establish a few of the usual arguments, to save everyone's time:
-A "Game" implies challenge, and a failure state (express or implied)
-"Not A Game" does not have to be a pejorative term! Perhaps these are better called "Interactive media", or Interactive Narratives or Galleries or Exhibits.
-A lot of people are irritated when they buy these, because they're sold on Steam to a bunch of games, and look like games.
-It might be good to decide what definitely IS a game (EG Checkers, where two sides compete to determine a winner and a loser) and what is definitely NOT a game (EG a visual novel which doesn't present any character decisions, and is almost the same as reading a book).
-Some more examples which might be useful for consideration: Most people would say that "Candy Land" is a game, but it involves absolutely no decision making whatsoever. "Choose Your Own Adventure" books are not usually called games, but they have decisions with consequences, including explicit success and failure. "Dear Esther" involves virtually walking around a computer environment and observing it without taking part- is this comparable to walking around a real, physical art gallery?
So, that's hopefully enough food for thought to establish a decent discussion. I bet we can establish a useful definition for what is and is not a game that categorizes all the examples in question- I encourage you all to propose what that example might be.
Oh yeah, and lastly, a few RULES:
-READ THE WHOLE THREAD
-Be Civil! An insult towards a game should not be taken personally. By the same token, we're not really discussing whether games are good or bad here, just whether they're games, so the mere fact that a game is not entertaining isn't that relevant.
-Remember: It's okay for something to not be a game! It can be something else, and still good.
Okay, go!