Green Switch Palace

The Green Switch Palace is a Switch Palace found on the west side of Donut Plains in Super Mario World. It is unlocked by finding the secret exit in Donut Plains 2. This level cannot be replayed after it has been completed.

Overview
The palace consists of two rooms, which the player has 200 seconds on the timer to complete. The first room has two levels. While the player can just use the above platform and take the Warp Pipe to the second room, which has the green ! Switch, there is also the option to hit the Switch Block and to defeat the Koopa Troopas on the lower level with a Red Shell. When all Koopas are hit at once, the player gets an extra life.

The second room contains nothing except the green ! Switch, which can be activated by jumping on it.

Gameplay effects
When the Green Switch is hit, all green Dotted-Line Blocks turn into Green Blocks, which contain Cape Feathers when hit. In later castles, a single Green Block often appears before the boss door, giving Mario or Luigi one more power-up before he faces a Koopaling. These blocks also help the player progress through the levels by filling in some gaps. The Green Blocks appear in only 20 levels after that.

Levels with Green Blocks
Green Blocks can be found in 20 levels:
 * Donut Plains 1
 * Donut Plains 2
 * Donut Plains 3
 * #2 Morton's Castle
 * Vanilla Dome 1
 * Vanilla Secret 2
 * #3 Lemmy's Castle
 * Butter Bridge 2
 * Cookie Mountain
 * Forest Fortress
 * Forest of Illusion 2
 * #5 Roy's Castle
 * Chocolate Island 2
 * Chocolate Island 3
 * #6 Wendy's Castle
 * Valley Fortress
 * Valley of Bowser 1
 * Front Door
 * Star World 4
 * Star World 5