World 4 (Yoshi's Island DS)

World 4 in Yoshi's Island DS takes place in the mountains of Yoshi's Island, becoming snowier and colder in the second half as Yoshi scales greater heights. In World 4-5, Baby Bowser encounters Yoshi and his party, and decides to join them on their adventure. However, this alliance is short-lived, as at the end of the world, Baby Bowser abandons the party as he attempts to go off with Kamek. World 4, like all other worlds in the game, has a total of ten levels; six regular, two hidden, and two bosses. The bosses in this world are Six-Face Sal and Big Guy the Stilted.

Level info

 * 4-1: Rock 'n' Fall – This level takes place on the cliffs of Yoshi's Island. Yoshi needs to jump across rocks while avoiding getting crushed by ones coming from above.
 * 4-2: High-Speed Cart Race – This level takes place on a high mountain. Yoshi uses a cart to progress through the level.
 * 4-3: In the Clouds – This level takes place in the skies of Yoshi's Island where Yoshi has to bounce on clouds to progress though the level.
 * 4-4: Six-Face Sal's Fort – This level is inside a fortress filled with lava and Fangs, the boss of this level is Six-Face Sal.
 * 4-5: Friend or Foe? – This level introduces Baby Bowser who can be used to melt ice and light up dark places.
 * 4-6: Slip Slidin' Away – This level is on a icy mountain and has a lot of Bumpties which Yoshi must avoid.
 * 4-7: Teeth-Chattering Chill Zone – This level involves using the slippery ice as an advantage and as something to beware of, the latter parts of the level introduces Ski Yoshi.
 * 4-8: Castle of Big Guy the Stilted – This level takes place in a Castle and involves using Baby Bowser as a shortcut to trigger things that normally require eggs, Big Guy the Stilted is the boss of the castle.
 * Secret 4: Hurry and Throw! – This level is inside a castle where the screen autoscrolls in a circle; Yoshi has to run around and collect the three Number Balls to open the door to the next section, where Yoshi has to jump off of the heads of Para-Koopas in the sky.
 * Extra 4: Let There Be Light! – A level which begins in a dark fortress with Spikes and Bullet Bills, leading to a space section with Flatbed Ferries, Spinners, and more spikes.