Severed Head PK

Severed Head PK (生首SC) is the name of a scrapped Famicom game for Yume Nikki. While little is known about the game, it is theorized it would have been a second game to be played in Madotsuki's real-world room, accompanying NASU.

Discovery
The only public evidence of Severed Head PK's existence is through the Thumbs.db image files found in version 0.04 of Yume Nikki. This version of the game was previously considered lost until it was dumped online by Gatobot of team #LaInvestigaciónYN on October 20, 2018.

While the Thumbs.db images found in v0.04 showed lots of unused or old content, the Severed Head PK images were some of several images that did not have a counterpart or final version seen in versions after v0.04. Reconstructions of the three images found to be related to Severed Head PK were reconstructed.

Gameplay
Nothing is known about the gameplay of Severed Head PK, as no playable version exists, though some theories can be formulated from the available Thumbs.db images.

One of the images appears to depict the game in action. It displays a grassy field, a soccer net, and a monochrome severed head on the field. A black bar with red text stating "PRESS ENTER" is also present. From this image, it's likely that the goal of the game was simply to get the head into the soccer net, which would be done by pressing the Enter key. To add difficulty to this task, it's also possible that the head moved on its own across the field, requiring for the player to time their button press in order to win.

Another image shows a select screen, though it appears to be empty save for a title and a mountain-like background. It is unknown what the player was intended to select on this screen, though it may relate to difficulty, stages, or the severed head's appearance. If the theory involving Severed Head PK's gameplay above is correct, it's likely this was too change the game's difficulty and thus would change how hard it was to get the head in the net (shrinking the goal size, making the head move faster, etc.).

Remnants and Theories
While Severed Head PK itself is not in the game, it still appears to have affected some aspects of the final version of Yume Nikki, despite not being implemented during the game's lifetime.

The Famicom select screen appears to be the most notable indication that more games were planned for the Famicom in Madotsuki's room, as NASU is the sole member of the game menu. The menu in this case becomes redundant, as NASU could also have simply been implemented by interacting with the Famicom if it were the only game planned. It's possible that KIKIYAMA planned to eventually implement Severed Head PK throughout Yume Nikki's development, but eventually decided against it.

Much like how NASU affects Madotsuki's dreams, some remnants of Severed Head PK affecting her dreams appear to have made it into the game. Some characters or aspects appear to resemble or allude to severed heads:
 * An event in the White Desert lets the player see flying heads moving in a rolling motion, which may allude to the game appearing to have a soccer theme with the head as the ball.
 * There is a large blue head gate found in Eyeball World. It takes the player to the Footprint Path upon entering. This gate also has a White Desert variant that can be seen when entering the desert from Block World. Eyeball World's background also depicts a figure holding a person's head.
 * The Henkei Shita found in the Footprint Path and Hell resemble headless bodies, with the black dot at the top of their head resembling where a neck would be.
 * There is a Guillotine in the game which gives Madotsuki the Severed Head effect. The Nopperabou effect also lets Madotsuki detach her head from her body.
 * The Mouth Monsters also appear to resemble severed heads, as they are shown to appear near blood stains and only consist of a round body, a mouth, and hair.
 * One of the Mall Shoppers, specifically the pink one with twintails, will become distorted upon interaction. While distorted and moving east, her head will pop on and off, which may also allude to this theme.

One other theme that may cross with the severed head theme found throughout the dream world may be allusions to indigenous imagery found in the game, specifically Aztec or Nazca culture, with the latter having detached heads as a common motif in their art.