On the far right of the stage there is a hill sloping upwards which reaches the right blast line. On the left there is a large, oblique Warp Pipe supported by two smaller ones. Between them there is a flat stretch of land at whose center there is a pit covered by three Rotating Blocks. Six more blocks float over the stage in two blocks of three.
If characters attack a block or jumps into it from below, the block starts spinning and can be passed through, becoming solid again after a short while. This can cause fighters to get trapped in the pit in the middle with little chances of recovery, especially in Ness's case.
The background features hills, moving clouds, berry trees and, occasionally, a Banzai Bill and a Fishin' Lakitu with their Super Mario World sprites. They have no gameplay effect.
In Brawl, playing as Fox, Falco, or Wolf and activating the LandmasterFinal Smash when at least one of the three Turning Blocks in the middle rotates causes the Landmaster to fall through the resulting hole, causing a Self-destruct, despite the fact that the Landmaster is much bigger than the opening. This is because of a game physic in which the actual character is still on the field and the characters cannot stand in midair. The Pokémon Trainer also occasionally moves above the hole, even though there is clearly nothing under him.
This stage comes from Super Mario World. In Super Mario World, there are these yellow boxes with two vertical line in them. If the player were to hit under a yellow box, the yellow box would spin for a short period of time. When the box is spinning the player is able to go through it. In this stage in Melee, there are nine of these yellow boxes. When a player hits or attacks the yellow boxes, the players are able to go through them. In Super Mario World, the player will occasionally come across a diagonal pipe. One of the diagonal pipes is used as cannon for the player to get across large gap. In this stage, there is a diagonal pipe. There are numerous elements in the background of this stage that are seen in Super Mario World such as round-topped mountains, apple trees, and long rounded clouds. In Super Mario World there are apple trees. When a player is riding on Yoshi, the player can make Yoshi eat the apples from the trees. When Yoshi eats a certain amount of apple, it lays an egg that has a certain item in it. Apple trees can be seen in the background of this stage. Also in the background of this stage are two enemies from Super Mario World. One of them is a giant Bullet Bill called Banzai Bill. The other enemy is a Fishin' Lakitu with an extra life mushroom.
There are two songs that can be heard on this stage. The first song comes from Super Mario World's "Athletic" theme. When the player jumps on Yoshi in Super Mario World a drumbeat can be heard. The drumbeat can be heard in Melee's remix of this song. The alternate song has a mix of two songs from Super Mario Bros. 3: the overworld theme and the song that plays when selecting a stage in World 1.
Yoshi's Island in Melee.
The middle part of the stage with some turning blocks triggered by the Ice Climbers and Diddy Kong, who is using a Golden Hammer.
The trophy of Metal Mario in Melee, if inspected closely, reflects a still image of this stage.
Attack a block so it spins, then pause, zoom in on the block and angle the camera. When these blocks are spinning, they become two-dimensional; this explains why characters are able to fall through them.
Super Mario World did have large diagonal pipes like the one on the left of this stage; however, all of them angled up and to the right, unlike this one which angles up and to the left.
Although Super Mario World was part of the main Mario series, in the Smash series this stage is part of the Yoshi universe. However, all Yoshi universe properties can also be considered part of the Mario universe, due to Yoshi having first appeared in a Mario game, and appearing in various others (especially sports titles and the Mario Party series) since then.