Remember the first time you played Super Mario Bros, and you just had to know what was on the other side of the flagpole? Surely there were adventures a-plenty, or at least a castle without some pointless retainer, just waiting for the best gamers in the world to time their leap perfectly and forge new adventures.
Well, we Game Genied that shit and you know what's on the other side? Nothing. A constantly repeating screen of nothing that you can't come back from. It's like a pixilated version of ICP's "Echo Side" where you are trapped until God (You) pulls the plug on the universe (The NES).
However, there are places that gamers were never meant to go that are actually worth the trip. Some you can actually reach via hacks and glitches, some no, but the best backstages in video game history are...
Still one of the greatest adventures of all time, Final Fantasy IV had a band of warriors attempting to stop an evil sorcerer named Golbez from using the crystals that controlled the elements to open a path to ultimate power on the moon. Theses warriors are, unfortunately, really, really bad at this, and pretty much actually make the villain's scheme even easier with each feat of derring-do.
At one point, Golbez is just one crystal short, and hoards them all at the top of the mind-bogglingly huge Tower of Bab-il, which we believe is still the tallest structure in the entire Final Fantasy universe. Our heroes make it all the way to the inner sanctum, they can see the magical glow of the crystals in their shrines, then all of a sudden a trap door drops them all the way back to the beginning of the maze. They decide to give up and go find the last crystal rather than climb all those stairs again...a move we have absolutely no problem with.
Here's the thing. Even though you only see the barest glimpse of the crystal room, it's fully fleshed out, and even has an empty spot where the last crystal will eventually go. What's more, there is a back door to the crystal room, a door that leads to another part of the tower that you can see while exploring normally, but can never get to. You can use a walk-through-walls code to get into the room, but trying to grab a crystal crashes the game harder than Michael Berry into a gay bar bouncer's car. To us that only means that somewhere in the enormous structure there is a path that will allow you to enter from that back door, retrieve the crystals and play a whole alternate-universe version of Final Fantasy IV.
Goldeneye on N64 remains one of the most perfect games ever created, and proof that what FPS fans want is for when we shot someone in the balls, we want them to grab their balls and make a face that expresses their inner monologue of, "Oh no! My balls! Bullets don't go there."
The first level instantly grabs you, and you may be keen to get to the iconic dam, jumping as soon as possible because everyone agrees that that scene is cool as the other side of the pillow. However, if you glance through your sniper rifle out into the opposite direction, there's an honest-to-God supervillain lair that's impossible to reach...without a GameShark, that is. Turn on the ability to walk on water, which officially closes the gap between James Bond and Christ, and it's out to the citadel you go.
Unfortunately, all it does is look cool. A boat was supposed to take you to this side quest, but the programmers ran out of time and cut it before it was done. They removed the boat to keep out trespassers, somehow forgetting that the people who were playing the game were pretending to be a super secret agent who can infiltrate anything.