Let It Go

"Let It Go" ("随它吧"/suí tā ba in the Chinese spinoff) by Disney's Frozen is featured on Just Dance 2015, Just Dance 2015 China (under a different name and language) and Just Dance Unlimited.

Classic
They're basically Anna (P1) and Elsa (P2) from the movie Frozen. Anna wears her pink cape, black and blue dress, and black boots, and Elsa wears her light blue sequin dress and blue kitten heels.

Sing Along
She's basically Elsa from the classic routine. She retains her features.

Classic
The official logo for Frozen first appears. During the verses, the dancers are in a snowy forest. During the choruses, the background is blue with light blue snow swirls and snowflakes across the screen. The dancer's reflections can be seen at the bottom. During the bridge, Elsa builds an ice castle. The background resembles the movie.

Sing Along
The floor contains a large light blue snowflake, which highlights and sparkles. Multiple snowflakes appear and disappear in the air. After the second hook, Elsa builds her ice castle from the classic routine. At the third hook, the background switches back to the snowflake floor.

Classic
There are 4 Gold Moves per coach in the Classic routine:

Gold Moves 1 and 3: Anna, cross your arms (like in Girlfriend and Lollipop). Elsa, put your right hand on your face, like a thinking pose. Gold Moves 2 and 4: For both dancers, bring your arms down forcefully. Anna, face the left and Elsa, face the right when the chorus starts.

Sing Along
There are 2 Gold Moves in the Sing Along, both of which are the same. Both: Throw both arms forward while stepping to the right when "Let it go" is sung.

Trivia

 * This is the third Disney song in the main series, after This is Halloween and Prince Ali. It's followed by Under the Sea.
 * Although she is not credited, this is the first song by Idina Menzel in the series.
 * However, the song was covered, which would technically nullify her original version's actual presence in the game.
 * The game uses a cover version of Nicki Gonzalez (Yao Beina in the Mandarin dub), although Disney's Frozen is credited for both games.
 * The dancers have a natural skin tone, akin to Hot n Cold and Prince Ali.
 * This song was leaked on both the PAL and NTSC box covers.
 * However, only the NTSC cover mentioned the specific song. The PAL cover only mentioned the 'artist'.
 * The song was revealed briefly in a private YouTube video.
 * The dance features several elements from the movie, including the background and the dancers (Anna and Elsa) preserved in their cartoon form.
 * P2 (Elsa) uses some moves from the movie Frozen.
 * This is the second time that a movie name appeared before the routine. This comes after Prince Ali.
 * Before the players start the game, Anna has her hands on her hips, but her pose was supposed to be crossing her arms.
 * A very short part of the Sing-Along was found in a Vimeo showreel, making this choreography leaked.
 * Both Classic Mode and Alternate Mode for this song were leaked.
 * Elsa leaves ice trails whenever her arms or hands are in action.
 * "The past is in our past", instead of the correct "The past is in the past", is seen in the lyrics.
 * This is the only female/female duet in Just Dance 2015 (recycled DLCs not withstanding).
 * This is the final track to be revealed through a gameplay on the Just Dance YouTube channel.
 * It is also the only track in the main track list to be revealed after the game's release and the final track list's reveal.
 * The lines "Don't feel" and "Here I'll stay" in the Sing Along routine become immediately unhighlighted after they are sung. In the Just Dance 2015 China version of the Classic routine, the Chinese line for Couldn't keep it in/Heaven knows I tried gets immediately highlighted, although Beina sings it slowly.
 * In the sing along, the song is titled "Let It Go" with quotations (the classic routine not having quotations) and the artist is "Disney Frozen" instead of "Disney's Frozen". Also, in the preview of the store, it says "#Disney" on the corner.
 * This is also the case on Just Dance 2015 China.
 * On Just Dance 2015 China, a Mandarin version of the song is used. The title is written as "随它吧" (Suí tā ba). It is currently the only Western song to have its audio altered for a foreign game, and one of the few times for any game.
 * On the Xbox One, the sing along routine came out roughly a month after it did on the other consoles.
 * This is the only song on Just Dance 2015 to have a downloadable alternate routine.
 * For some reason, the square of the Sing Along version is different in the shop than in the menu; it shows the dancer in a different pose and it can be seen that the dancer has lipstick. The lipstick is not present in the routine.
 * Similar to other songs with copyrighted dancers, being Prince Ali and Ghostbusters, the song does not come with an avatar that is based off one of the dancers in its debut. Instead, it comes with a snowflake avatar.
 * In Just Dance 2016, with the use of Just Dance Unlimited, an avatar based off of Elsa is available.
 * This routine is the fourth in the Just Dance series to have dancers with names, after Just Mario, Prince Ali and Ghostbusters. It is followed by Balkan Blast Remix, Ievan Polkka, You're The One That I Want and Under the Sea.
 * The dancers' skin tone is recycled in You're The One That I Want and Under the Sea.
 * The song's pictogram bar beats at a slow 69 BPM, even though the song's actual BPM is 137.