i never could get that crystal

I think you can use the Rock/Cutter mix to transform into random animal shaped rocks...

Eventually you transform into a sparrow which has flying abilities rather than Kirby's float.

Actually, you're supposed to use the hamster form which can walljump to the top.

Which, incidentally, I could never manage to do more than twice. :(

Only way to get that crystal was walljumping with the hamster. Kinda tricky, specially since I didn't know the haster had a walljump.
Just had to hold against the wall and keep jumping...

Internet solved that for me...

2D Samus = hampster?

His name is Rick. This shard was a callback to his appearance in Kirby's Dream Land 3, where he could walljump (and also had a very difficult stage where you had to escort him to the end of a heavy platforming stage in order to get a heart star). All of the animals made by Rock/Cutter were from KDL3, with Rick, Kine and Coo also originating in KDL2.

FFFFFFFFFF I HATE THAT PART!

I thought that the hamster could crawl up the wall instead of just wall jumping.

Use the rock sparrow, it was completely overpowered for pretty much anything.

The sparrow was Pitch and the hamster was Rick. Goddamn why weren't they in this game more...