From the rocky plains of Grass Land into a dark and dank cave, you have travelled through quite a variety of locales in the first world alone. A character from another game needs your assistance, and she will give you a Heart Star if you can help her out!
You will start off having to walk up an incline with many Rockies tumbling down toward you. If you get the Stone ability from them, you can also roll down hills too, destroying anything in your path. Down the first hill is a Health Drink surrounded by Star Blocks, with a raincloud hovering above. That raincloud is called a Loud, and it still attack by dropping water droplets at you. Get the Health Drink while evading the Loud's projectiles to replenish some lost health.
Continue to the right to see a Dekabu inside a pit. The Dekabu will leap up, spitting out smaller Kabus at you. Simply attack it so that it doesn't spawn any Kabus. Further on, you will begin to enter a tunnel. While there are plenty more Rockies, there is also a bat called Babut that will try to approach you and drain your health. Avoid it and defeat the other Rockies as you go toward the door at the dead end of the tunnel.
Into the cave
You will fall straight into a pool. Swim through the water to the right side instead of trying to fly over there, so that you're safe from the Babuts that fly around the cave's ceiling. Continue onward and defeat the many other Babuts. Soon you'll see a green enemy called a Kapar. They attack by throwing their hats at you, and you can get the Cutter ability by swallowing them. Past the Kapar is a room that contains Chuchu and Nago. Select your partner and continue right. You will have to swim through another pool, then jump into one of the green blobs to make them propel you upward. The left one leads you to a star, the middle one an Invincibility Candy and the right one a Maxim Tomato.
Hop into the green blob to let it shoot you up through the wall of blocks, then drop down to continue forward. As you go down the slope, watch out for a new hidden enemy, the Peran. This nasty trickster camouflages itself with the walls, and will briefly appear to throw an arcing blob at you. You can only defeat them when they're visible. At the end of a slope is a section of floor that can be broken with the Stone ability, which you can easily obtain it from the Rocky nearby. Once you drop in you can get a Health Drink. However, unless you are alone or teamed up with Coo, you won't be able to get out from this lower section, and will be forced to go through the lower door. Don't fret, as while the lower path is harder, it is also required to get the Heart Star!
If you went through the upper door in the previous area, you can simply skip this boss by walking through the separate path above its arena. For players entering the area through the lower door, they will have to fight Boboo. This huge fireball is the first mid-boss you will face in the game. It has only one attack, which is to repeatedly charge at you. It drops cinders when it rams into a wall, which you can inhale and spit back at it if you don't have a copy ability. Swallowing its body after defeating it nets you the Burning ability.
Heart Star: Reunite Chao with Goku!
The bearer of the Heart Star of this level is Chao, the heroine of Yuuyuuki. She was separated from her monkey friend Goku while exploring the caves, and it is up to you to find him. If you took the upper path, you won't be able to get to Goku. However, by going through the lower path and defeating Boboo, you will be sent to a corridor where Goku is. Simply walk up to him to collect him, fulfilling the requirement to get a Heart Star!
Climbing back out
Watch out for the yellow patched underneath every star here, as they are actually enemies called Oro. When you get close, they will turn into harmful spikes. Attack them from a distance to cross safely. After the Oro are a series of Glunks that drop into a shallow pond. These recurring sea anemones launch projectiles out from their stingers, but they are still pretty easy to defeat. Jutting out from the pond is a short ledge with a Health Drink as well as a falling chunk of rock. Wait until the rock is rising to collect the drink.
Continue across the pond while avoiding the Glunk's shots. Destroy the Star Blocks so that you can start ascending upward. This winding vertical path marks the first actual appearance of Gordos. While you've seen them as the balls used by the Pitcher in the previous level, they are now enemies in your path. Gordos cannot be defeated, only avoided. If you wish to get the stars this Gordo is guarding, jump up when it is going left and run right to collect the stars. Stay at the very end until the Gordo starts moving back to the left, then drop down and wait for the Gordo to move to the right before continuing forward.
The remaining portion of the path contains more Oros, some hanging from the ceiling this time. Take them out with care and run to the end of the passage, where another Gordo guards a Maxim Tomato. You can obtain the tomato without getting hurt using the same method as the one stated before. After that is yet more Oros and one more Gordo, this time guarding a 1-Up. The tactic to get the 1-Up is unchanged, so just get it and rush straight to the door.
Return to the surface
A Babut is perched on the ceiling as you emerge from the cave. Defeat it and run forward. A boulder will come crashing down from behind you! It rolls pretty slow, so keep calm and dodge the Gordo in front of you, then keep running forward. Jump up the small ledge to be safe from the boulder. If you can jump high enough, you can try to go for the Maxim Tomato behind some Star Blocks above where the boulder is located. Continue to the right, carefully dodging the many Gordos hovering around, until you reach the exit.