You need at least 6 Sun Stones to access this stage, which should be no problem if you're following this guide. It is the area's boss stage.
Star toward the upper right, and as you go, you'll gain an Assist Star. You'll also find a 3D Warpstar you can ride into the background to find capsules containing the Bell, Circus and Spear abilities. Pick the one you like, then return to the foreground.
Climb the ladder to your right, and then continue in that direction to find a large door. Enter it to begin a scene, after which point you'll be fighting the boss.
Boss: Paintra
This boss will use several techniques, which keep to a theme and involve paint. You can move in close when it is in the foreground and attack with your Spear ability or other weapon. However, be ready to retreat when it begins diving around.
Most of the enemy's attacks focus on preventing you from seeing what is happening. When paint is tossed and sticks to the screen, you'll have to watch carefully to see where your foe has gone, or you'll have to guess. You can still inflict damage here, if you're paying attention.
Another attack involves painting cannonballs on paper, then shuffling the paper to the top of the screen so that the cannonballs drop out of it. Yet another move finds Paintra spreading white paper over the background, then moving around behind it. Watch for the shadow, and keep moving to avoid being attacked when Paintra suddenly bursts through the paper and flies directly toward the screen.
There are other attacks of a similar nature to the above, and you'll find them relatively easy to avoid. Watch for multiple paintings to spread across the screen. One of the objects that appears within will usually be harmless, so get in front of it while the other monsters deal attacks. Attacks will grow more desperate as the battle wages on and Paintra's life meter drops, but as long as you don't take many hits along the way, you'll come through in one piece.
Once you win, a floating object will appear near the center of the ledge. Grab that pendant to finish the stage.
NEXT: Lollipop Land - Stage 6 EX