Yume Nikki is a game consisting of many interconnected locations that vary wildly in theme and size. One of the goals of the game is to visit them all and witness the many events that take place there.
The dream world is an intricate labyrinth of openly looping regions and obscure pathways, but most regions of the game can be considered as part of an individual 'world' with connections to other worlds.
This is a list of all the central worlds of Yume Nikki.
Note that in this wiki, the commonly-accepted fan names are used as the regions of the game have no official name.
A colorful world with floor tiles that chime when tread upon. When seen from a distance, the tiles form an Aztec-themed mosaic. The Bicycle effect can be found here, as well as the entrance to the Mall and the women's restroom.
A massive crimson labyrinth with many branching pathways filled with Toriningen. There are many connections to other areas, as well as a creature from the Footprint Path and a somewhat out of place vending machine.
A vast expanse of curly plants and arid soil, reviled for being very difficult to navigate. Many things, such as the Toriningen Party, the Aztec Rave Monkey, the Barracks Settlement, and the Towel effect hide inside.
Found through one of the igloos in Snow world, this area houses Poniko, as well as numerous colored balloons that teleport Madotsuki in and out of the water. The Frog effect speeds up movement through the water.
A somewhat obscure area accessed through the Staircase of Hands. The Umbrella or Yuki-onna effects are needed to extinguish the flames that block your path. The Poop Hair effect can be found here, along with the entrance to the Spaceship.
A red, rocky wasteland reached through the Spaceship. Traveling to the left will lead to a small steaming vent on top of a hill. The midget effect can be used to get to the boiler room inside. The UFOs on Mars event can also be seen here.
A small, looping area that houses the Severed Head effect and numerous lunatic Toriningen. Furthermore, there is a 1 in 8 change that you will end up in a much larger version of this area with eight lunatic Toriningen chasing after you.