Self-Referencing in Games

In my Modern Novel class today, the professor mentioned on an aside that postmodern novels tend to self-refernce themselves, making the reader aware that he or she is reading a book. I thought about it, and I have determined with fair certainty that all games have self-referential qualities.

I came up with this list of different instances of self-referencing:

Spelling out the game's controls, usually at the beginning -- Notable in pretty much every game I have played, games' beginnings lay out specific ground rules for how to manipulate the games' universe. This might be to press X to speak to an NPC (non-playable character) in an RPG or even the ever-present guide to the popular simulation/sports game, Wii Sports.

Characters noticing they are in game -- This is a much rarer instance, but I have noticed a few times in my gaming experience characters that seem aware they are part of a game. Sometimes characters spell out the controls to the gamer. Other times a silent character might look into the "camera" to express a state of unknowing. The classic example: "It's up to you to [insert epic goal here]!"

Humor -- Sometimes games will reference things that do not exist in that game's world. After creative a massively complex fantasy world, making a reference to something non-existent in that world (but existent in ours) would reveal that the game has self-awarenes.

Other examples probably exist, but these are the ones that come to my mind. This is another way how text in general is almost a living, breathing creature, adapting to and absorbing the world around it.