4th Wall Breakers

It's not especially uncommon for films or TV programs to have scenes in which someone looks at the camera and speaks directly to the audience.  Put simply, people on your screen know they're in a video.  However, it's much rarer to encounter a game in which the characters are aware of this.  There are a few noteworthy examples out there though which don't appear to be widely known.  So, I will mention them here.

Characters coming out of an arcade machine has to be one of the most obvious (and earliest) instances I can remember seeing the 4th wall broken in video games.  Mortal Kombat, in particular, had a mildly terrifying advert poster in which two of the fighters decide to take out their aggression on the players controlling them rather than each other.  Another example of this type of thing is the ending to the arcade version of Golden Axe.  Presumably through the use of magic, a variety of the characters in the game are able to escape into the real world.  One can't help but wonder what antics will follow.  The incredibly hammy film "Beastmaster 2: Through the Portal of Time" comes to mind.

Speaking of movies, another Sega arcade game called Altered Beast features a rather strange image in the ending sequence presenting the in-game characters like a bunch of film actors wrapping things up on stage.  Needless to say, it's a bit jarring not only in the sense that everyone was wearing a costume, but also because it implies that the game was actually a movie shoot.  Much later Konami would take a similar tact with the ending of Silent Hill by showing cut-scenes outtakes wherein somebody flubbed a line or is simply screwing around on set.        

For me, hands down the biggest fourth wall shattering video game company has to be Sierra and their adventure games.  It must have been in vogue at some point to do this kind of thing because a number of titles featured it around the same time period.  Leisure Suit Larry 3 had the aforementioned protagonist of the series retire from adventuring to become a game programmer making none other than Leisure Suit Larry games.  Space Quest 3 had Roger Wilco rescue the kidnapped creators of Astro Chicken only for the three of them to get sucked into a black hole and re-emerge near planet Earth.  Naturally, they just happen to touch down in Oakhurst, California (which incidentally is the place where Sierra On-Line Systems HQ was located), where the two programmers are hired on the spot by the (then) CEO of the company, Ken Williams.

Of course there were a number of other instances of this kind of thing before and after in both these IPs, as well as several other Sierra franchises like Quest for Glory 2: Trial by Fire and Police Quest 2: The Vengeance.  Overall, I'm not sure what to make of these design choices, but regardless I thought they were worth mentioning for the sake of posterity.