The menu had different score (it was blue), but it changed for unknown reasons.
The Mojo icon in the menu looked different in the early versions of the game.
The original menu scrolls faster than the released one.
In many previews for the game, the pictogram slider was originally going to have a triangle at the end that would flash to the beat. However, in the final version of the game, this was changed to just a rectangular spotlight at the end. The spotlight fully covers a pictogram when it zooms in and fades away.
Istanbul (Not Constantinople) was planned to have a Mashup, which appears within the game files, but not in the game. The reasons why this one was scrapped is unknown also. Some fans have seen the Mash-Up and a few of them said that it looks very strange, maybe because it only features 6 dancers.
The coach for Moves Like Jagger was supposed to wear only one outfit for the whole routine: this is proven by the Just Dance Now files, where there are red pictograms even for moves that are performed by the other version of the coaches.
In a showreel, the title appears in several colours whenever Moves like Jagger is sung.
In the game trailer, the 3rd coach has a purple outline.
On the NTSC cover, C4 is seen with a totally different color palette.
Beta background detail (part of the title appears)
There was a beta picture of Oh No!, where there were display stands for heels and purses, and it has hanging pants and paper ball lights and string lights, and was without the mannequin backup dancers.
In Puppet Master Mode, P2 makes an appearance as a "Strike The Pose!" picture, but her color scheme is a bit different: her hair and shoes are brown instead of purple, and her glove is magenta instead of yellow-orange.
So Good by B.o.B. was meant to be released as a DLC in April 2013; however, the game developers didn't pull it off for unknown reasons. All the files for the routine were uploaded in the Just Dance Now archives during 2014.
The menu assets were replaced with updated ones during 2015.
According to the script used in the Mashup of Ghost In The Keys, the files contain a Beta pictogram.
In the preview gameplay, the pictograms were red and blue instead of fuchsia and brown.
In the menu assets, the coaches are seen with a red outline, instead of a dark blue one.
As seen in a promotional screenshot, the background was somewhat simpler than in the final version: the scenery was more zoomed in, the light chunks were much bigger and emanated light rays, the spotlights and the flame effect in them were more faded and the blue smoke was absent.
In early versions, avatars simply consisted of a rectangular picture showing the coach's face.
If you look in the "Wheel of Gifts" section of the manual, you can see an unknown avatar behind the menu icon of the Extreme version of Wild Wild West. Looking at the form of it, it seems to resemble an astronaut. When the game was released, the only astronaut dancer back then was in Pump Up The Volume, so it's possible that Pump Up The Volume was gonna have a avatar available for Just Dance 4.
It also seems to have no face and a small, full body, which would explain why it was removed, since avatars only features dancer's heads.