Top Secret Area
From SMWiki
In Super Mario World, Level 3 is called Top Secret Area and is a secret level hidden above the Donut Ghost House in Donut Plains. It is a single screen with the side exits enabled. It features five ? Blocks, two on the left holding Fire Flowers, two on the right holding Feathers, and one in the middle holding a Yoshi. It has no time limit.
It is accessed by entering Donut Ghost House with a Cape power-up and flying up the far left side of the room to get over the ceiling, upon which Mario can walk over the large mass of ghosts and to a special chamber holding four 1-Up Mushrooms and a secret goal.
In Super Mario Advance 2, the Top Secret Area is shown with a smiling green hill rather than the normal yellow circle.
In the original Super Mario World, this stage had no time limit, while in Super Mario Advance 2, the time limit was set to 200 seconds.
[edit] In Hacking
Top Secret Areas (with a similar or identical function to the official one) are very common in Super Mario World hacks. Super Demo World: The Legend Continues featured several hidden mushroom shops that functioned identically to the Top Secret Area, although each featured a bonus extra item such as a Koopa Shell or Star that could be stored for later use.
As they have become so commonly used (with some hacks featuring multiple yet identical Top Secet Areas), they are considered by some to be a cliché, especially when they are the only secrets hidden in the game's overworld.
