Yume Nisshi Wiki

Crystal World

The Crystal World is a place decorated with large different colored crystals that are placed in buildings and on the ground. There is a tall building with the crystal on the top floor will that links with the Mural World via the Painted Hall. The crystal world is also accessible by interacting with the blue crystal found in the Blue City; this a one way entrance though.

In total, not much can be done here other than examing the beautiful crystals and machinery found everywhere.