Update 1.9

Update 1.9 is an upcoming update for Geometry Dash. It will be out for the Android, Windows Phone, Amazon Devices and Steam. Its speculated to be released late October. The level Blast Processing has been confirmed along with Theory of Everything 2. Some people have been saying the update will be coming out on the 30th of December, but there is no official date.

Prior to the release of the 1.8 update, Robert Topala said in a conversation at Touch Arcade Forums:

"I have a lot of ideas for update 1.9 that could be huge for the game, but more on that after I release 1.8... muahaha"

Preview
On August 13, 2014, Topala posted his first sneak preview image, showing five icons wearing different-colored headphones. It was revealed in a future hint image that it represented the custom music option and likely the icons may not get headphones.

On August 26, 2014, Topala created another image depicting three-dimensional blocks, arousing much excitement among Geometry Dash players. He continued with the idea on August 28, posting a picture on Facebook about what could be built using the blocks.

On September 6, 2014, another image was posted through Topala's social media accounts featuring several different new map components that would be used in future levels of Geometry Dash. This included two new icons, gear-like obstacles, and various different unknown types of blocks. The most prominent feature was a new thick blue portal that would likely result in another game mode being introduced. It was also released to the public that Topala would release the game to Steam, a popular internet-based social media platform.

====On September 14, 2014, RobTop released an image on Facebook. It has a blast and processor for Blast Processing by Waterflame and a book, an infinity symbol, and a "2" for Theory of Everything 2 by DJ Nate, with Theory of Everything 2 likely to be the Demon level, following similar lines to Update 1.6.====

On September 21, 2014, another image was posted through Facebook and Twitter for the new "Custom Music" feature that will allow players to include music from Newgrounds in their custom levels. The image includes 10 icons with headphones at the bottom. It was the first picture to indicate that the update was work in progress. Upon the release of the image, Topala said that a sneak peek video for the next levels would be coming soon.

On September 28, 2014, Topala officially released the sneak peek video. The new, blue portal changed the icon to an arrow-like object similar to Wave Wave. It featured the level Blast Processing.

On October 10, 2014, he also officially released another sneak peek video featuring the level, Theory of Everything 2. Upon closer look, the sneak peek has a background tunnel-like and a new design of ship was used. Topala was also using a mouse to do the video, indicating that he may have been using the to-be-released Steam version of the game.

New Stuff
Unreleased - the following are presumed:
 * New levels "Blast Processing" and "Theory of Everything 2"!
 * New game mode!
 * Ability to give blocks a 3-dimensional appearance
 * New icons
 * New background and art
 * Geometry Dash Update 1.90 Sneak Peek 2-0 achievements to complete
 * Ability to give blocks individual colors
 * Invisible slope objects
 * Custom songs from Newgrounds
 * Level length, height and block limit increased (to 15000)
 * User Profiles
 * New Blades

Trivia

 * The new arrow form was inspired by the mechanics of the mobile game Wave Wave. It is supposed the concept was brought to light by popular player, Darnoc, who created a level (also named Wave Wave) mimicking its mechanics using condensed groups of gravity rings with the UFO.
 * This is the first update that included a second version of a main level song: Theory of Everything 2
 * This is the second update that includes two new main levels. (1.6 with Electroman Adventures and Clubstep, and now 1.9 with Blast Processing and Theory of Everything 2)

Links

 * https://www.youtube.com/user/RobTopGames (YouTube Channel)
 * https://www.facebook.com/geometrydash (Facebook Account)
 * https://twitter.com/RobTopGames (Twitter Account)
 * http://forums.toucharcade.com/showthread.php?t=203823 (Touch Arcade Forums)