Ever since Super Mario Brothers brought side scrolling levels to the masses, gamers have been running through the world without ever looking back. Kick a turtle shell to the left, and run away to the right for safety. Narrowly jump over a Hammer Brother and keep moving until he's off the screen and out of your life forever. Even though the majority of levels made nowadays aren't 2D side scrolling, they do have a starting point and an ending point with little to no backtracking.
Today I want to focus on the kind of level design that isn't about leaving things behind. I want to focus on a type of level design that is like climbing a tall tree to rescue a cat; going one way provides one kind of challenge (ie. climbing a tree), and getting back is a different challenge that builds upon the original challenge by adding a layer of depth/complexity (ie. climbing down a tree with a cat in one hand). I call this kind of level design folded level design.
Folded level design is different from back tracking, or playing new level/scenario that uses a familiar environement. Back tracking is simply traveling along previously visited paths and areas and usually involves the same challenging game elements as the original pass through. In other words, back tracking is simply going back without any significant changes or surprises. Likewise, reusing an environement from a previously visited environement is merely making a new level at a fraction of the effort.
Folded level design is like like folding a piece of paper; the two halves cover the same area but there's an addition layer to consider. For example... on your way to the kitchen you had to dodge all kinds of domestic objects that are now hazards in the dim lighting. But on your way back, you must to reconsider your approached due to the glass of water you are carrying in each hand.
The genius of folded level design is in how it develops a set of knowledge for the player and then manipulates it. In the cat tree rescue example, climbing up a tree is a challenge due to gravity, footing, and visibility. While ascending, one would gather knowledge about the arrangement and strength of the branches. Using both arms and legs, one would climb up the tree one step at a time. Upon reaching the top and with the cat (the crease) in hand, the challenge is folded. The crease is simply a term for the point at which a level folds upon itself. Now the climber has one less arm/hand to use, the pole like branches are transformed into downward steps, and the cat must be protected from stray branches. In this scenario, the knowledge of climbing branches is reanalyzed. A great path going up, could be a risky path going down.
In a video game, a level can be designed so that a player must perform certain actions before the level folds upon itself. Doing this is a safe way to ensure that the player has enough information to make the best decisions once the next layer is added. The clearest examples I can think of come from the Metroid series. Instead of using text boxes to explain what each power up does, the levels are design in a way so that the player "traps" themselves getting a powerup and then must use that powerup to escape thus self teaching the function of power up.
Perhaps it's best just to show some examples.
- Wario Land 4: Layer 1. Crease and Layer 2. In this game players delve deeper into each level searching for treasure and other monetary goodies. Upon reaching the end of the first half of the level, players must activate a switch that sets a timer for Wario's escape. The switch is the crease that folds the level back upon itself. The additional layer is the timer and the small blue bricks. These bricks will either switch on or off depending on their state before activation. The barriers created from these bricks help guide the player along their way back through the level.
- Boktai: Explanatory video. In this game, players journey deep into buildings/dungeons to retrieve sleeping bosses. The game can be played like an action game, but in true Kojima style stealth is the best course of action. Once inside the building, players must conserve their energy. At the boss, or the crease, players grab hold of the coffin and attempt to reverse stealth back outside the building. With coffin in hand, players travel extra slowly adding an extra layer to the mix.
- Pikmin 1 & 2. In Pikmin, like in most RTSs, players spend their time traveling away from their base to gather treasures/resources, fight battles, or scope out the area. Unlike in other RTSs though, Pikmin is designed to create dynamically folded gameplay in a more open world style. In general, players can seek out prized objects any way they want. If they so chose, players can sneak around enemies, climb over obstacles, and jump down from higher platforms to reach treasure. The catch/crease occurs when players order their Pikmin to carry the treasure back to the base. Not only do the Pikmin carry the treasured object very slowly, but they're completely vulnerable as they take the shortest path back to base. If you're not careful, Pikmin can easily walk themselves into hazards or bump sleeping enemies. Even if the path the Pikmin take is completely clear, some enemies can be accidentally coerced out of their "zones" and wander into places you never expected them to be.
- What's even more dynamic though is, in the event that the player cuts their losses and calls their Pikmin back from carrying the treasure, the treasure will drop and stay in that location until the player moves it again the next time. Depending on how long the player waits to return to it, enemies can repopulate areas. So the next time you go back for that treasure, the challenge may have changed considerably with new enemies to guard it. For all these reason, the folded design in Pikmin is made up of dynamically intersecting folds upon folds thus achieving a multi-fold design or origami level design.
- Zelda Phantom Hourglass: This game is filled with folded level design probably because of how folded level design makes more use out of a limited space which is ideal when designing a handheld game. The battle mode is in essence an extension of the RTS style gameplay found in Pikmin. Furthermore, having to carry around the boss keys and switch gems to progress through the dungeons folds the level upon itself by adding the extra layer of Link's limited mobility and limited use of his weapons. The best example is probably the Temple of the Ocean King. Each time you visit this dungeon, Link's new abilities transform the strategies and possibilities for completing it. In some cases, they allow Link to reach new areas. In other cases, they allow Link to bypass sections reducing the progression time considerably. The notes players can write on the map are persistent which keeps the temple from completely resetting when the player leaves. Because the player must journey out of the temple to gather new items and abilities, playing the rest of the game can be thought of as the crease. Because the temple unlocks quests on the over world and visa versa, Phantom Hourglass as a whole achieves a multi-fold design or an accordion design.
- Zelda Twilight Princess: Temple of Time. Going up is a challenge/puzzle in itself. Once players obtain the Rod of Dominion and take control of the giant statue (the crease) at the top of the tower, the challenge is to get the statue back down. The descending challenge is more complex because of how Link controls the statue remotely with his own movements, the statue's limited mobility, and great weight. This temple is easily one of my most memorable Twilight Princess levels.
- The final castle in Zelda: OOT and 4 swords. You go up to do battle, and have to come back down with Zelda in your party. Protecting Zelda adds the additional layer in this folded design.
- Perfect Dark: mission 1,3. The first mission is all about infiltrating the dataDyne building using stealth. After retrieving the AI in the second mission, players must escape from the building by reversing the path they used to infiltrate it in mission 1. The new layer for the escape mission is that the whole building has been alerted to you presence and guards are waiting for you with traps. At the first step off the elevator, the lights are cut and players have to navigate in the dark while avoiding the barricade traps. The 2nd and 3rd mission in Area52 have a similar folded design.
- Super Metroid (and almost all other Metroid games): Speed Run. The design of Super Metroid's world involves a perfectly balanced amount of backtracking and discovery that is powered by Samus' transformative abilities she gains along the way. With each power up, Samus gains a new way to dispense enemies with as well as a new way to move through the environment. Ball form can fit into small holes. Bombs and missiles can blast open new passage ways. The speed booster or super run provides new ways to move through a space including straight up. This super run can also power through obstacles turning a bumpy road into a smooth track. Perhaps the most genius element of Super Metroid's folded level design is how these abilities create momentum and suspension between the game's distinct sections bringing what would other wise be independent level section into one cohesive flow of game ideas.
- Mario Kart Series: Because of the circular design of all race tracks in Mario Kart, items and traps left on any lap but the last lap are folded back into the game. Lay a bunch of bananas on the skinny bridge on DK Parkway and you might be the victim of your own deviousness. The layers are created from the "leftovers" on the track as well as the finish line. The pressure of finishing in first place puts a sort of fluid/dynamic timer on the gameplay experience that's relative to whoever is in first.
- Super Mario Bros. 3: World 7 castle. World 8 castle. One of the revolutionary new features Mario Bros.3 added to the series was the ability to move left or right at any time. Gone are the days of not being able to go back to see if you missed something. There are a few levels that use this feature to the max. In these levels Mario is stuck in an small series of distinct sections that loop in some way back into themselves. The strategy involves utilizing the respawning power ups from multiple pass through the looping level to gain the flying abilities needed to escape.