Update 2.1

Video previews
Note that the following videos are not officially endorsed by the Geometry Dash Wiki and are only being used to give insight about likely features of Update 2.1.

Previews

 * May 26th, 2015: Robert Topala makes his first mention of Update 2.1 on TouchArcade, saying "I wanted to mix up the art style a bit, keep things fresh. More craziness in 2.1!". Because of this statement, it is assumed that there will be new decorations and blocks.
 * September 22nd, 2015: Robert Topala entered Zobros' stream on twitch.tv and set up a Q&A. He mentioned that a new jump ring will be added, as well as a new anti-cheat system that allows the game to take progress (stars) from the player's stats when they use hacks.
 * September 30th, 2015: Robert Topala posts the first teaser for the update. The image shows a new four-legged gamemode, resembling a spider. Later, Robert Topala confirmed a new indigo coloured portal would be the new gamemode.
 * October 29th, 2015: Robert Topala posts the second 2.1 WIP picture on Twitter.
 * November 9th, 2015: Robert Topala replied to a question that there won't be a demon level in 2.1. He also says he will try to release 2.1 before the year ends.
 * November 13th, 2015: Robert Topala entered dak2014's stream on Twitch and made a Q&A. He said that a "secret project" (later revealed to be Geometry Dash Meltdown) would come out before 2.1 and he hoped that they would both come out before Christmas. He also mentioned that 2.1 wouldn't be too big. Additionally, he stated that the new features of 2.1 will be a new gamemode, a new gameplay ring. (presumably a new kind of jump orb, as stated in his Q&A on September 22nd), a new level (not of demon difficulty) with new music by a new composer, bug fixes, and small extra features.
 * December 1st, 2015: Robert stated on a Twitch user's chat that the new secret project (Geometry Dash Meltdown) will contain icons transferable to Geometry Dash by the press of a button, however Geometry Dash-exclusive icons can't be transferred to the new app.
 * December 11th, 2015: On TouchArcade, Robert stated that Update 2.1 will be pushed back to January 2016 as he is still fixing things such as new triggers, bugs, etc. But he has announced that Geometry Dash Meltdown will be released on December 19, 2015.
 * December 16th, 2015: In Cyclic's Twitch stream, Robert mentioned that the 2.1 song teaser would be released after Geometry Dash Meltdown comes out.
 * December 21st, 2015: 2.1 is added to Geometry Dash Lite on Google Play, with a new level xStep.
 * January 2nd, 2016: Topala posts the third 2.1 teaser on Twitter and Facebook, which hints the soundtrack for the new level.
 * January 4th, 2016: RobTop entered Xenonetix's stream on Twitch, saying that 2.1 should be released in early February 2016. He also adds that new map packs and animated enemies will be added to the game in 2.1. He talks about some new things coming in a future update, like the scale trigger and the collab system, and the new rotate trigger and how it can spin an object around an axis.
 * January 5th, 2016: 2.1 is added to Geometry Dash Lite on iOS, adding a new level, xStep, and some achievements.
 * January 27th, 2016: RobTop says on Toucharcade that there's going to be a new vault. He also said that there will be two types of rotation for the rotation trigger: To spin around axis or to spin around the target.
 * February 2nd, 2016: Topala said that a sneak peek for the new level will be released very shortly and announced that Update 2.1 is close to being released. He wants to make sure he fixes bugs, tweaks and hacks etc. before releasing 2.1.
 * February 4th, 2016: Topala posts the fourth 2.1 teaser on Twitter, Facebook and TouchArcade, and says that the 2.1 level sneak peek is almost ready. The image showcases a bat/dragon-like monster (which could possibly be new "monsters", and be a threat to the player) a new background, a new waterfall decoration, new stone blocks and a new blue diamond decoration, which could have some gameplay function. RobTop also apologizes on Facebook for being a bit slow.
 * February 9th, 2016: On Krazyman50's stream on Twitch, Topala provides a link to a picture of the 2.1 level editor. The picture displays a new interface for selecting colours, using three bars for hue, darkness, and brightness of the colour. Topala also mentions possibility for a new rating system, where each level is rated on 1 to 10 out of different categories. He stated: "In a new rating system you would have rating scores for different areas. So 1-10 for visual, 1-10 for gameplay etc." He also confirmed that the new blue diamond shown in the last teaser will have some gameplay function and will not be just a decoration.
 * February 16th, 2016: Topala says that 2.1 may be delayed until March due to minor fixes and tweaks. He also said the sneak peak will be released soon.
 * February 21st, 2016: RobTop uploads "Fireballs?" on his YouTube account, which shows off more new upcoming features from this update. The first of many features depicts rotating fireballs around a block, confirming that there will be a rotation trigger in 2.1. Then there is the bat/dragon-like monster, which is animated and it is shooting a fireball from its mouth in a horizontal position. After that is an animated waterfall, followed by an invisible outline of a square. Next is another bat/dragon-like monster, which is animated and is seen shooting a fireball from its mouth in a diagonal direction. A new dark purple-coloured portal is seen next, which is likely the portal for the new gamemode, a new ground and a new background are also noticeable, and new rock decorations as well as particle decorations that are scattered throughout the level, hinting at a new particle editor (something that RobTop mentioned previously). Finally, an image of what likely could be the new vault appears. The new music that could be for the new vault plays throughout the whole video, and is not the level's song, which is proved by to the music continuing after the gameplay.
 * February 28th, 2016: On Xaro's Twitch Stream, RobTop stated that there will be exactly 3 new jump rings in 2.1. Two have gameplay functions (like all pre-2.1 rings), and one is a custom ring. He also explains that jump rings like "kill orbs" will be possible, as the custom ring works like a trigger.
 * March 4th, 2016: During GDSkitten's stream on Twitch, Robert Topala shares more insight on what 2.1 will bring, sharing how you can control the animation of some monsters, and tells about a possible "touch" and "count" trigger. He also mentions a possible collision trigger, saying that the player could shoot objects, but probably won't be included with 2.1, but maybe 2.2. Lastly, he says that Geometry Dash Meltdown will be updated after 2.1 with a new level, and a new collaboration system could be implemented after that as well.
 * March 16th, 2016: RobTop confirms that the new indigo coloured portal at the end of the Fireballs? video is the new "spider" gamemode.
 * March 24th, 2016: After entering GironDavid's stream on Twitch, RobTop mentions 4 new orbs, and that one will be a custom trigger orb. He also stated that there are possibilities for a new challenge mode, and the reason why 2.1 got delayed was because he had to remake some features since he did not like the way they looked. He also continued on to say that the new "spider" gamemode is finished (confirming it will be called "spider mode") . RobTop went into detail about the orbs, stating that one of the orbs is a variation of a current orb, not the green one, and that one orb will work like a "toggle" trigger if tapped. He restated that the other two orbs were gameplay balls.
 * In a private conversation, RobTop says that he might add teams and chats when he gets the time (possibly in a future update).
 * Later RobTop entered Riot's stream and mentioned that there will be a sneak peak. He also mentioned making extensions to the featured section. There will be a 2.1 daily feature and there will be a special featured spot for the level that gets featured. he said that the level must be rated, and that if completed on that day, diamonds would be awarded, which unlock icons and achievements. RopTop finally said there will also be three new skins for keys.
 * "Slightly Special awards" will give you diamonds, and how many you get is based off percentage.
 * March 30th, 2016: On GuitarHeroStyle's Twitch stream, RobTop posted a link to an image depicting a pink fire-like trail around the player. He also mentioned he may raise the object limit to 35k (by 5k). Later, on TouchArcade RobTop mentions that the sneak peak is soon to come, and that he is working as fast as he can on the update. He also mentioned that the level will not be named after the song Fingerbang, that you can change the colour of the fireballs, and that the custom trigger orb is just like the triggers we already have, but they need a jump ring for activation. It is mentioned that the epic colour is being added, but it is tricky (implying it will take time), that he will consider a favourite level list, and that he might do a shorter sneak peak of the level, and then make another video showing off the spider. He also said in a private conversation during GuitarHeroStyle's stream that "Live multiplayer" may not be added.

Trivia

 * The icons that are featured in the second sneak peek picture are only 2 of the many icons that can be unlocked in Geometry Dash Meltdown. This is related to an upcoming feature in which Meltdown icons can be synced to the full version with a player's account.
 * Update 2.1 currently has the longest amount of time between two update teasers. The time between the second 2.1 WIP image (October 29th 2015) and the 2.1 song hint (January 2nd 2016) was over two months.
 * This might be due to the release of the "secret project (i.e. Geometry Dash Meltdown)", released between these two dates (December 19th, 2015).
 * It has been stated by RobTop in an unknown twitch stream that the song MDK - Fingerbang presents a more inappropriate and vulgar name than any other level presented in the game. The level's name (if this were the song for 2.1) will be changed in order to be suited for the appropriate young teen audience (citation needed).
 * The black bat-like enemies displayed in teaser 4 closely resemble the random enemy idea shown by RobTop just hours before the release of 2.0.
 * RobTop stated before 2.0 that he would focus on making future updates only take 1-2 months. However, it has been nearly 8 months since Update 2.0 was released with very few teasers and sneak peeks.
 * The editor in the fifth preview image oddly has two "edit object" buttons. This is likely just a mistake, or the second "edit object" button may be used for the new colour bars shown in the picture.
 * The pink trail on the sixth photo is also the fireball that the "bat" spat out on the example video. This could mean that the fireball cannot kill the player itself and might need a spike hidden inside the fireball.
 * The square pink particles are most likely part of the fireball, but may be a new trail for the icon as it is in mid-air rather than on the ground.

Geometry Dash Lite Introductions

 * New Level "xStep"!
 * New achievements and rewards!
 * Bug fixes and tweaks.
 * Removed hacks and exploits.
 * Added secrets...