As with several other games, the Just Dance series is no exception to having its own Easter Eggs. Here, you can browse through all the Easter eggs which Ubisoft has so kindly put in the Just Dance series.
What defines an Easter Egg?
An Easter Egg could be anything - something that unlocks additional content, "cameos" from dancers outside from their own song; really anything that can be considered "secret" or "bonus" content. They could even be beta elements (although this page should be left for the best of beta elements as there are already pages for that). Also, see songs with the title in the background for more Easter Eggs.
By playing all the songs in Just Dance Wii, Just Mario is unlocked. A 1-UP sound can be heard when unlocking it.
The Beta silhouette of When I Grow Up appears in the Multiplayer menu of Just Dance Wii, although the song is not in the game.
Just Dance 3
The first ever Extreme version could be unlocked in this installment of the game by keying in the Konami Code (with the exception of A and B). By doing so, the Extreme version for Barbra Streisand would be unlocked and become playable, although it faced glitches.
Baby One More Time has a possible Beta dancer which appears in the Mashup for the song. Although she does not make an appearance in the song, people have made guesses that she might have been a beta dancer for the song.
At the start and end of Call Me Maybe, when the screen zooms out to show the entire background around the phone, the lyrics from the chorus and the coach from Mas Que Nada can be seen in small text near the top right of the screen.
Besides, one of the icons in the phone shows the AutoDance logo - AutoDance is an app developed by Ubisoft.
The coaches for Y.M.C.A are all returning dancers from other games. P1 is the coach from Rasputin from Just Dance 2 and P2 from Hungarian Dance No. 5 from Just Dance 3, P2 is C3 from Moves Like Jagger from Just Dance 4, P3 is the coach from Viva Las Vegas from Just Dance 2, and P4 is the coach from Dare from Just Dance. They all have been slightly updated and are in higher quality.
P2's avatar of Sway (Quien Sera) reappears in an achievement of the game called "I ain't afraid of no ghost!", which can be gained by playing Ghostbusters as Slimer (P4), because it resembles Stay Puft from the omonyous film.
Raving Rabbids and characters from Rayman Origins appear in the background of Love Is All.
In Only You (And You Alone), a binary code which translates to 49 can be seen in a bottle in the background of the choreography. It is currently unknown how the number 49 relates to Just Dance or Ubisoft for that matter.
They also recycle clothes from previous routines in the series: P2 recycles the jacket from the fanmade routine of Turn Up the Love, P3 recycles the shirt from Rock N Roll and P4 recycles the jacket from DADDY.
The coaches from Animals reappear in the Alternate version of RADICAL.
In the 7th-Gen version of the game, there is a tutorial picture that shows a girl wearing P1's helmet from Animals and a boy wearing P4's unicorn head from 4x4; the routine projected on the screen reuses the background from the Classic version of Sorry.