Update 2.1

Previews
Note: If you want your info to be verified, you must have a source link (pic. or website) in the same post
 * 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.
 * October 29th, 2015: Robert Topala posts the second 2.1 teaser picture on Twitter.
 * November 9th, 2015: Robert Topala replied to a question on TouchArcade, stating that there will not be a demon-rated level in 2.1. He also said he would try to release 2.1 before the end of 2015.
 * November 13th, 2015: Robert Topala entered dak2014's stream on Twitch and initiated a "Questions and Answers" activity. 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 would not be a big update. Additionally, he stated that a few of the new features of 2.1 will be a new gamemode, the Spider, a new gameplay ring (presumably a new kind of jump orb, as stated in his Q&A on September 22nd), a new level with new music by a new composer, bug fixes, and small extra features.
 * December 1st, 2015: Robert stated in an unknown 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. He also announced that Geometry Dash Meltdown will be released on December 19, 2015.
 * December 16th, 2015: In Cyclic98'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. The teaser depicts a gray Mario, a plus symbol, and a gray Donkey Kong. On the right, the teaser shows an orange outline of a hand with it's index finger escalated being added to a radioactive waste symbol. Based on this, it was assumed, and was confirmed on April 16, 2016, that the song is Fingerbang by MDK.
 * 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 discusses 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 it's 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 a new vault will be added in 2.1. He also says 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 peek 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 spider 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. RobTop 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 GuitarHeroStyles' 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 GuitarHeroStyles' stream that "Live multiplayer" may not be added.
 * April 6th, 2016: On Xaro's Twitch stream RobTop said that he added a new "auto-building" system for the new stone blocks since they can be pretty complicated to build. He mentioned that the sneak peek is getting close and that the new orbs will be revealed in the sneak peek. He also said that there might be different ways to earn diamonds besides the daily featured level.
 * April 7th, 2016: On Mazl1997's Twitch stream, RobTop said that there will be a new trigger that toggles the player's visibility state, such as making the player invisible. RobTop also said that there will be a lot of new icons and vehicles. (Source's link needed.)
 * Later, in an unknown Twitch stream, RobTop confirms that the official level in 2.1 is rated Insane.
 * Later, on RioT's stream, RobTop mentions that there will be a block that the wave can slide on, and visual lines in the editor that show when an effect ends, art has been tweaked a lot, the sneak peak is very original and different from the "Fireballs?" video, and that there may be a new system in which you can add your own art. This system will require verification as photos added into the game must be appropriate. Afterwards, Robtop says the fireball is a gameplay effect.
 * April 9th, 2016: In ASonicMen's Twitch stream, RobTop stated that he made a function where when you press it, it automatically changes the group of an object(s) to the next free group. He then goes onto TouchArcade and informs that there will be no option to cut or crop songs in 2.1, but maybe in the future. Later on, he joins Manix648's stream and says that object limit hacks will no longer work in 2.1 and the object limit has been raised to 40k.
 * April 10th, 2016: In Sandstorm's Twitch stream, RobTop said Update 2.1 will have achievements for 8 and 9 star levels, there will be new demon packs, possibly before 2.1, the new level will have around 12 stars, more icons for beating online levels, there may be emotes for the comment section, and a top comment sorting option. He also says that all verify hacks, object limit hacks etc. will be banned in 2.1 and that there will be new user coin achievements. RobTop also stated that he will not be working on any more ports to other operating systems for Geometry Dash, he referred it as "its a lot of boring work."
 * April 13th, 2016: On Mazl's Twitch stream, RobTop explains how a challenge mode could work if implemented. He says that one player would challenge another on a randomly selected level with a chosen amount of stars. The player who beats the level in the least attempts, or gets the most percentage in a set amount of attempts is the winner. By winning, you climb the "global ladder" and gain a rank. He also said that there may be unlockable practice songs in 2.1.
 * April 14th, 2016: On Riot's Twitch stream, RobTop says there might be a challenge mode, and that he indeed explained it the day before. He also confirms mini icon customization. He also said that he is working on the sneak peek, and that it is very close.
 * Later, on an unknown twitch stream, RobTop confirms that one of the new orbs added will kill the player.
 * April 16th, 2016: RobTop releases a sneak peek, confirming the song as MDK's Fingerbang. It showcases 3 new orbs - a dark gray one, (which acts like the blue orb but doesn't switch the player's gravity), a triangular lime one, which may force the player along the lime trail or as long as he/she holds down and a triangular red one which forces the player forward so long as you hold down and switches the player's gravity. The red orb also may create a grayscale effect which turns the everything on the screen (the player included) to black and white for a split-second, but this could just be a color change or a new color trigger. There are also decorational signs showing different icons. It also showcases the new "spider" game mode, which appears to act as a ball, but with instant teleportation which appears to flash upon touch. The sneak peek also shows a new red jump pad which acts similar to the pink and yellow jump pads, but with a larger boost (around 6-7 blocks). It also shows new decor such as blocks and signs. The sneak peek also shows a new cube icon as well as a new shake effect. It also has an extension to the animated dragons added in 2.0, showing one with its mouth wide open, and the other one and with fire coming out, unlike the default movements, where the dragons just open and close their mouth following to the music's beat repeatedly. It also showcases the new rotation trigger and the new monster manipulation mechanic. There is also a new laser beam hazard that is made of zig-zags. It also has actual lava seen rising, which isn't the 2.0 water decoration as a red/orange color. The black bat/monster hybrid is featured too. Finally, around some blocks, there are small, white "star" shaped particles that have an animation. The animation has 4 white triangular beams that seperate in different directions and dissolve, then the animation starts over in the center where the 4 beams moved from before.
 * He later enters TouchArcade and posts another preview picture, depicting the ball vs spider movement. It also shows some new art for the buttons, and also some new buttons such as 'Copy Values', 'Edit Special', 'Paste State' and 'Go To Layer', and also a button with the picture of the background, ground etc. 'triggers'. These buttons appear to be more Boomlings style - almost resembling the buttons at the bottom of the screen (Rotate, Swipe, etc.)
 * Later, on Mazl's Twitch stream, RobTop announces some of the new features in 2.1. First, he said that the new level editor object limit in 2.1 has been raised to 40,000 objects. Second, he stated that he might raise the custom object limit. Third, he said that he added an option in the level editor called the "Swipe cycle select mode" where in if you have swipe disabled and tap on a group of objects multiple times, it will cycle what objects are selected. Fourth, he said that there is a new option called "Editor hold to swipe" which is mostly for mobile, wherein when not in swipe mode and if you press and hold for a small time, an indicator will show that swipe mode was triggered and it will now act like swipe mode is enabled. Finally, he explains how the dash orb works, stating,"It goes as long as you hold."
 * April 17th, 2016: On Riot's stream RobTop posts a link to a video showing off blue dash orbs, the spider, and a new icon that resembles the 60 user coins icon. The video is assumed to be "for spider haters" showing how the spider is different than the ball, because at the end of the test level in the video RobTop has text saying "Do that with the ball..." followed by "Kappa". RobTop also said that there will be a secondary object limit of 80k but it will have a warning icon. He also said it will depend on amount of RAM the game is using.
 * The video also confirms that the new dash orbs can be used diagonally (Possibly by Rotation).
 * The dash orbs shown in the video are also a different color than the ones shown in the sneak peek.
 * The video was also posted on RobTop's Twitter account on the same day. See post
 * He also states that the game is much more optimized now, and low-end devices will have less lag in levels with many moving objects. RobTop also added another low detail mode that will be in settings.
 * April 19th, 2016: On Pasiblitz's stream RobTop says that the shaking trigger will contain 3 inputs: Shake strength, Interval and Duration. He also mentions about tags and warnings, which will be implemented in 2.2.
 * April 23rd, 2016: On an unknown stream RobTop confirms that 2.1 will be released tomorrow for Steam, Android, and Apple.

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 has the most sneak peeks than any other update.
 * 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 will be changed in order to be suited for the appropriate young teen audience (citation needed).
 * Fingerbang is one of the four songs in the Geometry Dash series that cannot be found on Newgrounds. The other three are The Seven Seas, Viking Arena, and Airborne Robots, all by F-777 (Geometry Dash Meltdown)
 * The black bat-like enemies displayed in teaser 4 and the sneak peek 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 over 9 months since Update 2.0 was released.
 * However, there have been many sneak peaks and spoilers, and RobTop stated that during January, he decided to recreate many parts of the update as they did not appeal to him.
 * 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. Which was later fixed in a later preview image.
 * The trail caused by triangular orbs strongly resembles the fireball that the "bat" spat out on the example video.
 * Update 2.1 will be the first update since Update 1.8 to introduce an insane level, as Update 1.9 and Update 2.0 both introduced harder and demon levels.
 * The new level will be the fourth level to have 12 stars.
 * Update 2.1 will likely have the shortest amount of time between the release of a sneak peek and update, as RobTop mentioned that the update was ready for review by Apple before the release of the sneak peek.
 * Update 2.1 will introduce the most orbs of any update, with three shown in the sneak peek and another 'custom' orb mentioned by RobTop on TouchArcade as well as the 'kill' orb mentioned in an unknown twitch stream.
 * Update 2.1 will be the third consecutive update to feature a new game mode, with Update 1.9 introducing the wave and Update 2.0 introducing the robot.
 * There is only one known spider which is the default skin. However, Robtop mentioned in an unknown Twitch stream that there will be more spiders (about 4-5).
 * Along with Clutterfunk, Polargeist, Hexagon Force, Cycles, and Viking Arena (Meltdown), the new level does not start at the beginning of the song.
 * Update 2.1 contains the most new gameplay elements (orbs, pads and a new gamemode).
 * The new level will be the third main level that is not named after the song, after Clubstep, which is titled "Club Step" on Newgrounds, and Blast Processing, which is titled "BlastProcess" on Newgrounds.
 * Waterflame's YouTube upload of Blast Processing has that name as a title, however, so this only applies to Blast Processing on Newgrounds.
 * It is also likely that the level name will not be similar to the name of the song like the other two.
 * The grey/black orbs have eight segments in their rings unlike the others, which have two (or four in the case of the green orb).
 * Their individual particles are also able to spin on themselves (like the green orb's individual particles) unlike the other orbs' (even the triangle ones) individual particles which never spin on themselves.
 * Red and Lime triangle orbs shown in the 2.1 update sneak peek seem to light up the player at the start and end of the jump, unlike other orbs. but this may just be an effect as RobTop mentioned that he would add a trigger to change how the player looks.
 * This update also is the first update since update 2.0 to introduce a different shaped orb. In update 2.0, green rings were added and they have one ring and one dashed ring around them. Yellow, purple, and blue orbs have two full rings.
 * The triangle orbs have only one complete circle around them instead of a complete one and a segmented one around that.
 * The red triangle orbs may be able to change all of the colors to grayscale, as shown in the sneak peek. However, it is also likely that the grayscale effect is just a color change.
 * The red triangle orb may be a customized version of the lime triangle orb which could explain why the red orb flashes green
 * The red triangle orbs flash green when the player uses them. This might be because they are a hidden green gravity orb mixed with a colored red green triangle orb.
 * This could also mean the red triangle orb changes the players gravity, as the green triangle orb keeps it the same.
 * Update 2.1 has currently the longest sneak peek at 37 seconds. The second longest was the 1.8 sneak peek, at 33 seconds long.
 * As of 2.1, Fingerbang has the second latest start in it's song, starting at 34   seconds into the song. Clutterfunk currently has the latest start, being 0:43 seconds into the song.
 * In the sneak peek, the level has signs with arrows, symbols, etc. RobTop confirmed that the signs will be customizable in a stream.
 * The test video posted on April 17, 2016 does not show up on RobTopGames' YouTube channel because it is unlisted.
 * The triangle orbs might have a hold limit since if the player holds too long it might make it easier to cheat.
 * Update 2.1 and Update 2.0 are tied for the most amount of sneak peeks that aren't of levels; both have two. However, 2.1 has the highest percentage, with two thirds of the videos not being of levels and 2.0 having two fourths.
 * The level sneak peak contains a dragon that doesn't close it's mouth. This was not possible to do in 2.0, this is most likely made from the new animation trigger mentioned by RobTop.
 * Upon using the "dash orb", the fireball surrounds the player and uses the primary color.
 * The ball and the spider have the same screen limits.
 * The sneek peek shows a star-like object around some orbs. This could be a new auto-rotate object, or a custom object with a rotate trigger attached.
 * The lava blocks from the fourth WIP image are different than the lava blocks from the sneak peek.
 * According to the info button text, "There is a DARKNESS coming", this is probably referencing the cave-themed setting of the new level, which is very dark.
 * The icon used in the Update 2.1 sneak peek might be the icon for completing the new level, or an icon for unlocking user coins, as RobTop stated that there would be more coin achievements.
 * The picture taken on April 22, 2016 was taken after Level 21 (which uses MDK - Fingerbang as the song) was produced, as there are 22 dots (including 'Coming Soon').
 * The picture was also taken on Steam, hinting that the update is almost ready to be released.

Geometry Dash Lite Introductions

 * New Level "xStep"!
 * New achievements and rewards!
 * Bugfixes and tweaks.
 * Removed hacks and exploits.
 * Added secrets...
 * New options added.