Chapter 6, also known as Chapter 0 and The Moon, was a proposed sixth chapter to World of Goo. The events would have taken place on the moon and chronologically one year before the Epilogue. It was initially planned to be released with Europe PC version, but was scratched when 2D Boy decided to make World of Goo retail and WiiWare release.

Apparently it will be released in a sort of update pack. Kyle Gabler explained that,

The elusive Chapter 6 is on hold, and I’m happy to say that all versions of the game will be identical and we won’t have to rush to finish extra content just to justify a price tag. If we release any additional content, we will make it available on all platforms, to all people, at the same time. No more of this “region” nonsense.

As long as we’re talking about extra content, it might be worth mentioning some of the amazing things our community has done. They have created a level editor, misc parameter editors, a tower viewer, and my favorite - an open translation project to get the game running in as many languages as possible. And it looks like they are actually creating an additional chapter all on their own. To support them, Ron and I are working to make the game more moddable. I’m curious and a little scared to see what they come up with.''

—Kyle Gabler
[World Of Goo(d News) at]

Story behind Chapter 6

Spoiler warning: Plot and/or ending details follow.

The Moon was a prequel to World of Goo, taking place “one year ago” when World of Goo Corporation was a brand new Web 2.0 startup company, and they decided to monetize the Moon by making it ad-supported with community features. Eventually they detonate the moon, and replace it with M.O.O.N. 2.0, a giant ball of homogenized glowing/flickering Goo Balls, to create a giant hi-definition LCD panel in the sky for displaying important animated marketing messages to the World of Goo down below. The plot is told through a love story, involving “The Architect” who changes jobs at the end, and becomes one of the characters we meet in World of Goo.

—Kyle Gabler
[2D Boy interview at]

The Architect is rumored to be one of the main characters and seemingly, the player's only friend, the Sign Painter.