approved, was to have a huge tower acting as a central hub, with the height at which Link jumped lengthening the duration of his free fall. Once the concept of traveling from the sky had been chosen instead, the Loftwing mounts were created so it looked and felt more rational to players. These overlapping gameplay mechanics triggered the creation of Skyloft, along with elements of the early game such as the Knight Academy. The continual movements and routines of Skyloft's people were modeled after similar time-driven mechanics from The Legend of Zelda: Majora's Mask, with similar links between character-specific side quests and the main narrative. Despite the aerial element, the mechanics necessary for free navigation meant a Loftwing racing minigame could not be implemented. Each Surface overworld had a specific theme: the forest overworld revolved around landforms altering gameplay, the volcano overworld focused around changing the rules of gameplay, while the desert overworld was themed around duality between past and present. The first areas, the Sealed Grounds and Faron Woods, were created so players could be eased into the game's mechanics and navigation. While the forest areas were made to be mostly flat, the Eldin Volcano overworld was made with height differences in mind to provide a greater challenge. Elements in the volcano terrain included areas of lava and slopes where Link's sprinting ability would become necessary for reaching new areas. For the Lanayru Desert, the team created three different overworld zones due to its unique time-shifting mechanics, triggered with Time Shift stones: this shifting between different zones was inspired by similar systems in Ocarina of Time and Twilight Princess. The portable Time Shift stones were one of many ideas included in the desert overworld as they did not fit with the forest or volcano environments. A difficult feature to include naturally was the remnants of Lanayru's Ancient Civilization, which used electricity to power both its technology and citizens. Enemy types that recurred in all Surface-based overworld areas were given slightly altered designs so they would be unique to each overworld. The Silent Realms were created as a new mechanic, filled with enemies that could not be defeated and relying on Link's sprinting ability rather than his weapons or items. While they had experimented with indestructible enemies in Phantom Hourglass and Spirit Tracks, but this time it was changed by restricting Link's options and actions. They also created a time