When you begin the level,
it's a good idea to steal the boomerang ability from a Sir
Kibble. When you get the chance (most likely on top of the
castle), spit it out to combine it with another Sir Kibble
for the double boomerang ability. Going into the castle,
you'll find a room with a green barrier from a shard. Whip
out your double boomerang ability and bust the barrier
down.
Shard 2
Upon reaching the part of
level where Kirby is going around the fountain on stairs,
go back to the entrance passage and fly up. On top of the
passage is a shard in clear view!
Shard 3
The third and last shard
of this level, is temporarily under the possession of King
Dedede. In his right mind, King Dedede still doesn't want
to give it up, but does. After grabbing the shard from
him, he'll reluctantly join your party.