The player controls a girl named Madotsuki and explores her dreams, collecting 24 effects that change her appearance and equipment.

Yume Nikki was distributed as freeware on Kikiyama's personal website in June 2004, with updates continuing until 2007.

[2][3] The game's ending, unlocked after the player collects all 24 Effects,[1] shows Madotsuki jumping off of the balcony of her apartment.

[2] On January 10, 2018,[6] Yume Nikki was released on Steam by publisher Playism, and Kadokawa Games, the developer of the RPG Maker software, confirmed that Kikiyama was still alive and involved with the project.

[8] Yume Nikki received positive critical reception for its unique, surreal visual style.

[9] Wired's Julie Muncy also pointed to the game's surreal imagery and said that it appeals to those interested in dream interpretation.

[2] The gameplay and atmosphere were also well-received by critics, who identified the game's emphasis on exploration as a major appeal.

[1][9] Muncy described it as being "rich in atmospheric dream worlds" and said its surreal world-building logic creates uneasiness in players.

[9] Originally receiving a limited Japanese-only release, Yume Nikki later gained a larger cult following in the West, due in part to its fan-made English translation.

[4] Due to the game's open-ended nature and the accessibility offered by the RPG Maker software, Yume Nikki has inspired the creation of a number of fangames, some of which have attempted to explore theories about the original game;[1] notable fangames include Yume 2kki[c] and .flow.

[13][14] The light novel is titled Yume Nikki: I Am Not in Your Dream,[d] and was written by Akira and illustrated by Aco Arisaka.

[11] PC Gamer reported that the manga and light novel were criticized for providing explanations for things the game had left open to interpretation, and the Yume Nikki merchandise distributor stated that the adaptations were not created as canonical extensions of Kikiyama's original ideas.

[1] Along with the release of Yume Nikki on Steam, a two-week countdown appeared on the Kadokawa Games website.