Fall, or Autumn, is an unlockable alteration in Super Mario World and its Game Boy Advance remake, Super Mario World: Super Mario Advance 2. This event changes the appearance of certain enemies, and it alters the color palette of the overworld map of Dinosaur Land to reflect the season from Spring. The theme is unlocked by completing Funky in the Special Zone in Super Mario World; in Super Mario World: Super Mario Advance 2, it is unlocked by completing all 96 exits.
Once these prerequisites are reached, the changes will take effect, preceded by a short cutscene in the GBA remake: Luigi is shown on a hot air balloon tossing masks down with a message stating "Mario and Luigi have found all of the goals. Congratulations!!! Now you can play a slightly different Dinosaur Land!" After this, Mario is seen running, where he jumps on a Koopa Troopa and takes its shell. A mask falls, and the Koopa walks to it and starts wearing it. The scene then cuts back to Luigi tossing masks, with Caped Mario attending Luigi. Super Koopas then appear, where they then carry a large sign saying "Congratulations," and Mario and Luigi flash their V sign to the player.
Once Fall is activated, these changes cannot be reversed unless the save file is deleted and a new game is started.
In Super Mario-kun, in Chapter 7 of volume 2, Mario gets shocked by an ON/OFF Switch and wakes up in a dimension where the Yoshi's Island is in Fall. Mario is stunned, seeing the strange enemies (especially the Koopas with his face) and a violent Yoshi. After creating a giant shockwave with a Dragon Coin, Mario wakes up in the normal world, happy to see his brother and a gullible and always hungry Yoshi. In the next chapter, Mario, Luigi, and Yoshi face against a Jumping Pumpkin Plant, although in the normal world and not during the Fall.
Fall causes Dinosaur Land to change color, with green objects becoming orange-brown and brown places becoming green. Everywhere on the overworld map is affected, including places such as the Valley of Bowser. Although all of Dinosaur Land is changed, the water on the overworld map remains the same color, and the visual appearance of the levels is not affected. The intro of Super Mario World: Super Mario Advance 2 will show Dinosaur Land in Fall at the start and end.
Various enemies have their appearance changed in Fall. This change affects everywhere else in the game enemies appear in, including on menus and during the credits. These changes affect their aesthetics only.