7. Undertale
https://www.youtube.com/watch?v=9Kt2f5Lw21I The most unnerving kind of fourth wall-breaking games are the ones which don't tell you that they're doing it. Undertale is one such game. Undertale knows everything you're doing. Everything. If you've reloaded the game from a save point, the game knows about it and will make references to it, even making it a part of the narrative. You become revered for your godlike powers of saving and loading by other characters. If you restart the game from scratch, Undertale knows about that too. Flowey will berate you for going back on the decisions you made on your earlier playthrough. There's even talk of the game knowing when you're streaming it. This could be a case of reading too deep between the lines of some of the character's dialogue, but when they say things like "I bet someone like that's watching right now, aren't they?" you can't help but wonder. All of this makes you acutely aware of every decision you make. You never know when they could crop up later in the game. It speaks to the love and attention to detail that went into the game's creation. Simply addressing the concept of mechanics like saving and loading as a part of a game's universe adds a layer of meta awareness not found anywhere else.