World 1-3 (New Super Mario Bros. Wii)
World 1-3 is the third level in New Super Mario Bros. Wii. This is the first level to feature Yoshi as well as Hammer Bros. It is unlocked by completing World 1-2, and its own completion unlocks World 1- and a Yellow Toad House. There is also a secret exit in this level, which leads to a Warp Cannon. The Ground Theme plays throughout this level, with a special drum line added whenever any player rides a Yoshi.
The level is set in a grassland like World 1-1. There are platforms that use a similar design to the regular ground but are lighter to indicate that they can be passed through. There is a Hammer Bro on a set of Brick Blocks above some Warp Pipes stuck horizontally into the ground. The player will then find Yoshi for the first time. Yoshi can eat fruits off trees; when he eats five fruits, he will release an egg containing a power-up. The first Star Coin is found right after, then there will be a set of three Koopa Troopas and six Goombas, which can be used to get a 1-Up. Next is a small pit followed by another block containing Yoshi Eggs, then two rows of blocks, which a Hammer Bro jumps on. The midway point is located after this, followed by the entrance to the second Star Coin. Outside the exit to the hidden area is a Pipe with a Venus Fire Trap, a few Goombas, and two Koopa Troopas. Yoshi can be used to spit one of the fireballs to get up to three 1-Ups. The player must then continue down the course, past a few Hammer Bros., until they reach the flagpole.
Secret Mini Mario cave
If a player makes it to the checkpoint with the Mini Mushroom power-up active, they can enter a pipe half-submerged with a mini-pipe sticking out of the bottom. The secret room has two Koopa Troopas and many coins.
The secret exit can be found shortly before the third Star Coin, just after the Venus Fire Trap. The player needs to jump to the high cliff edge leading to a hidden passage. Once the player reaches the entrance point, they need to jump over the passage above the screen and travel across the top. At the end of this path is a hidden Pipe, which will send the players to the red flag. The secret exit will take the players to the World 1-Cannon Warp Cannon, which will send them to World 5.