Mechtropolis

Mechtropolis is the eighth world that the player will encounter during the run. It is currently the second or third to last world. Null's status as a world is debatable, so depending on whether you consider it a world or not, Mechtropolis is either the penultimate or the third to last world.

The Vigilante Droid makes its debut in Mechtropolis, being exclusive to this world. Higher variants of some droid types that appear become even more common, such as the Cyro 3.0 and Pyro 3.0. Xero 3.0s can also appear, but only from Mystery Buttons or if other Droids are rerolled with a game die.

Environment
Mechtropolis is an urban city street. The floor is a black road with grey walkways at the sides. The brick walls alternate between red and blue. Environmental objects that appear in this world include cars, trash cans and street lamps. The world takes place at night, unless a lantern or The Illumina is used.

Mechtropolis lacks environmental hazards. However, it has Turrets. Turrets naturally spawn in certain rooms and always spin around, making a full cycle once every 10(?) seconds, with its direction of rotation determined by the color of the turret. It shoots out bullets at a rate equivalent to Rapid-Fire Droids, dealing 5 damage each bullet. Turrets are indestructible and their direction and speed of rotation cannot be affected while active, but they will be permanently disabled after their respective room is cleared.

Turrets may spawn in the middle of the room or on top of cars. Like Rapid-Fire Droids, they cannot aim upwards or downwards, and their bullets can be nullified by the Golden Shield. The player can stand on top of turrets without taking damage.

Trivia

 * Mechtropolis is a portmanteau of the words "mechanical" and "metropolis".
 * Mechtropolis is the only world named this way.
 * Mechtropolis and Null are the only worlds that do not have two separate words in the name. Both have one.
 * The name Mechtropolis, although derived from two words, is technically one word.
 * Mechtropolis is the only world where the color of the walls changes from room to room.
 * It alternates between red and blue.
 * Mechtropolis used to have 10 rooms with enemies, as it was the last world (aside from Null) before the addition of Atomic Factory.
 * As of Atomic Factory's introduction, Mechtropolis now has 9 rooms with enemies and a shop as the last room.
 * Mechtropolis is the last world that naturally occurs at night.
 * Mechtropolis, The Darkness and Mount Whirl are the only worlds with no environmental hazards, if you do not count the Turret as an environmental hazard.
 * The song that plays in this world is called Scattle - Inner Animal.