Dark Matter's appointed ruler of Cloudy Park must have a pretty high rank, as he gets a flying castle made of clouds just hovering in the sky. The boss likes to flaunt his artistic talent, and drawings of Dark Matter's minions can be seen scribbled across the walls. A shape creature also inhabits one of the rooms of the castle, but imitating it will require a bit of flipping things around.
The strawberry cloud
The starting section seems calm, with no enemies other than the fake ones scribbled on the walls. Going through the door in the first area leads you to a section of a room that is blocked off from the rest. Also in this room is a wizard enemy called Madoo. It will target your horizontal position and send a black orb at you, which can actually destroy certain blocks. You must use Madoo's attacks to let you into the main part of the room, then to open up the cache of stars and the section with the door to the next area. If you accidentally killed Madoo, go through the first door then back into the room to make it respawn.
The cloudy castle interior
Past the first Madoo room is a long, winding section with plenty of Shotzos. Destroy the Star Blocks beneath each Shotzo to proceed, and try to dodge any shots they launch at you. Collapsing blocks separate each vertical level, and you can attempt to only break the one closest to the wall so the other acts as a shield against a nearby Shotzo's cannonballs. After the Shotzo area is another Madoo room. You enter through the leftmost door, and exit through the rightmost door. Each of the three middle doors have an Animal Friend, the left door contains Nago, the middle door has Coo and the right door has Rick. Again, if you killed Madoo before the door you need to go through is accessible, you can exit and reenter the room to make it reappear. The following section is a straight hallway littered with Propeller eggs. As you might have just gotten yourself an Animal Friend, watch out for the ones that home in on you extra fast.
Heart Star: Sculpting an inverted shape
After the corridor of Propellers, you will see a door. Go through it to see an upside-down creature shaped like a goblet. Just like in Ripple Field, there is another room with a cluster of Star Blocks that you must use to copy the shape of the creature. However, note that since the creature here is upside-down, the image you're trying to create must be flipped 180 degrees. Between the room with the creature and the Star Blocks is a hallway populated by Mopoo, which are very tricky to avoid due to the lack of space in the hallway. Once you get to the room with the Star Blocks, simply recreate the shape of the creature. You will hear a positive jingle once you succeed.
Toward the heart of the castle
Continuing onward. you will arrive at yet another Madoo section. This room gets trickier though, as there are five doors, but the position of the doors does not correspond to the place they send you. The exit is the second door from the right, but you can enter the rest of the rooms to get stars if you really want to collect them. One room contains a Como, the other contains two Ticks and the last one has a falling stone block. Past that section is a rest area filled with Bukisets. Swallow the Bukiset on each level to obtain their respective copy abilities, letting you destroy the blocks next to the Bukiset and obtain the items behind them.
You're back in a Madoo section, but this one is more simply, being a copy of the first Madoo room. Just use Madoo to get the stars and access the door that will take you to the final part of the level. You will reach what looks like the starting section of this stage, but with a odd twist. Some of the enemies on the walls will spontaneously come to life, so procees forward carefully to avoid being taken by surprise. The enemies themselves behave like their actual counterparts, and are similarly harmless, so you should get to the exit with minimal damage taken. Watch out however, as this is only a brief glimpse of the Cloudy Park boss's strange ability...