Crystalline Caves

Crystalline Caves is the seventh world the player will encounter during a run. (Unless the player is doing World 7 Darkness) Pyro Droid 3.0 and Cryo Droid 3.0 start appearing in this world. Many people like to skip this world by killing the World 6 Shopkeeper.

Environment
The caves have a dark blue floor and dark blue walls. The world takes place at night time, restricting vision unless the lantern or the Illumina is used.

Crystalline Caves' environmental hazard is lava. It is visually and functionally identical to the lava found in Violent Volcano. The Cinnamon Sword and the Elementalist's second ability can still be used to freeze lava, but there are no Freeze/Melt buttons.

Crystals are the primary feature of the world. They are large, glowing crystals with small cubes on the top of them. Crystals will bind to all Droids in the room, granting them forcefields (invulnerable to damage) until all crystals are disabled by destroying the cubes on top of them.

However, crystals also restrict the Droid's movement to a certain radius around the crystal, meaning that the Droids have restricted movement until the crystals are disabled.

Crystals come in two types, blue and pink. The blue crystal binds to Droids tightly, forming a rigid cyan bar between the crystal and the droid. This bar forces the Droid to remain a fixed distance away from the blue crystal, meaning it can only move along the limit of the crystal's range, so it will not be able to reach players that are on the crystal. Pink crystals bind to Droids loosely, forming a link that acts more like a rope. Droids are free to move anywhere within the crystal's range, but still cannot stray too far away.

Droids can still use special abilities while linked to crystals. If a Droid is bound by multiple blue crystals, it will be rendered immobile and can only stand in place until all but one of the crystals are disabled. If a Droid is bound by multiple pink crystals, the droid can roam anywhere within the area where the crystals' ranges overlap. A droid bound by a blue and pink crystal may only move along the range limit of the blue crystal but cannot leave the range of the pink crystal.

When a crystal is disabled, it immediately stops supplying invincibility to all droids in the room (if it is the last crystal). However, there is a delay before the crystal's links disappear, so the player can still attack the droids while they are vulnerable for a brief moment. This is helpful against Hunter Droid s, as they can be easily killed before they are released to charge at you. After the delay, the crystal will no longer link to any droids, but will still remain there as an environmental object.

Trivia

 * If a droid is linked to two blue crystals it will usually be suspended in midair until one is disabled.
 * Crystalline Caves is the first night map encountered on a normal run, not counting The Darkness.
 * This, The Darkness, Mechtropolis and technically Null are the only worlds to naturally occur at night.
 * Violent Volcano and Crystalline Caves is the only world with an alliteration in their names.
 * Coincidentally, both worlds feature lava.