One topic that I didn't see it address: should your game be replayable? For many (most?) of my favorite games, movies, and books, I don't really care about experiencing them again. The first time through was delightful, and then I'm happy to move on and try other things.

It's great if your game is replayable, but not all games need to worry about replayability. And even if your game is replayable, it should still be fun even to people who only play through once, without locking core mechanics behind endless repetition. And the pursuit of replayability is no excuse for trying to get your players addicted; players should feel free to stop when they've had their fill, without any pressure to consume more.