Lock block

A lock block is a stage feature in the shape of a capsule imprinted with a keyhole from Dr. Mario World. When a color capsule matches the color of a lock block or that it is eliminated, any cages of the same color as that lock block will be removed, allowing any previously-locked objects to be eliminated or interacted with. These only appear in stage mode.

In-game description

 * "Unlock the lock block to unlock the cages."

Gallery
Serratura