Birthday

Not to be confused with It's My Birthday.

"Birthday" by Katy Perry is featured on Just Dance 2015.

Appearance of the Dancer
The dancer is wearing a pastel-schemed costume. She is wearing a pink and sky blue top with sprinkles, a yellow and pink layered skirt, yellow polka-dot stockings with pink cupcake prints and blue high heeled boots. She has long marigold hair tied in a ponytail braid and is wearing a floral wreath made of teddy bears and button flowers. She is wearing very heavy makeup consisting of blusher and eyeliner.

Background
The background also has a pastel scheme. There are also pictures of cake and confectionery appearing. It is supposed to give the dance a Birthday feel. You can see many macaroons around and you can also see them with candles lit.

Gold Moves
There are 5 Gold Moves in the routine:

Gold Move 1, 3, 4 & 5: Throw both of your arms up in the air while you lift up your right leg.

Gold Move 2: Jump up and hold both hands out as if confused.

Mashup
Birthday has an unlockable Mashup with the theme "Best of Katy" and only features dancers from Katy Perry songs.

Dancers
(No repeats)
 * Birthday (JD2015)
 * I Kissed A Girl (JD2014)
 * Hot N Cold (JD)
 * Waking Up In Vegas (JD2014)
 * California Gurls (JD3)
 * Teenage Dream (JD3)
 * Firework (JD2)
 * Part of Me (JD4) [GM1 & GM2]
 * E.T. (JD3)
 * Dark Horse (P2) (JD2015)

Party Master Mode
Birthday has a Party Master Mode available. Here are the captions in order of appearance.

(Captions in bold indicate a Song Switch.)
 * Birthday
 * Purple Punch/Model Walk/Fluo Clock/Lonely Walk
 * Angry Teen/Why Me/Street Robot/Snap Dance
 * Hippie Mill/Cute Wrestler/Pendulum Whip/Clean Up
 * Glamorous Walk/Sunny Cross/Disco Hips/Crazy Slide
 * Cross Jumpy/Crossfire/Built For This/Maps
 * Take My Hand/Puppet Self Control/Violent Walk/Electro Chill
 * Fit My Knees/Angry Girl/Hippie Shake/Running Cheerleader
 * Move Like Eighties/Futuristic Stretching/Modeling/Girly Balance
 * Come Here/Release My Head/Haunted Arm/Side Walk
 * Let's Moonwalk/Prisoner/Don't Move/Up And Down
 * African Dance/Energetic Girl/Built For This/Holding Out for a Hero
 * Cute Smash/Hippie Fight/Release Me/Be Sweet
 * Charismatic Distress/Tiger Claws/Run Like Eighties/Dog Lock
 * Serious Fitness/Glamorous Jump/Puppet's Holding/Feel The Groove
 * Stupid Balance/Running Weird/Skiing Back/Why Me
 * Elegant Lock/Catching Disco/Happy Cheerleader/Fast Run
 * Hippie Wave/Too Cool For You/Holding Out for a Hero/Summer
 * Delicate Stretch/Explorer On The Ground/Rain Dance/Eighty Slow
 * Come On/Djole/Forgot My Legs/Disco Waves
 * I'm So Soft/Feel Bollywood (Glitch)/Cheerleader's Storm/African Mill
 * Electro Chill/Happy Rasputin/Summer/Maps
 * Be The Wind/Enjoy And Slide/Radical Geometry/Stay Away
 * Explorer's Lash/Cardio Training/Wake Up Mind/Catch The Fur
 * Hippie Ragga/Dog Walk/Weird Rythme/Feel The Groove
 * Hourra/Wipe Away/Shoot The Light/Super Crazy Shake
 * Birthday

Trivia

 * This was revealed in the ESRB's rating summary. The following 3 lines are referenced as suggestive:
 * "Pop your Perignon"
 * "So let me get you/In your birthday suit"
 * "Boy when you're with me/I'll give you a taste"
 * However, none of these lyrics were censored in-game.
 * "Pérignon" is a brand of wine, "Birthday suit" refers to nudity, and "I'll give you a taste" refers to a French kiss.
 * This is the 10th Katy Perry song in the series, The first being Hot n' Cold in Just Dance, second being Firework in Just Dance 2 (as a free DLC), third being California Gurls in Just Dance 3, fourth and fifth being E.T. and Teenage Dream respectively as Just Dance 3 Best Buy exclusives, sixth being Part of Me in Just Dance 4 and Just Dance 2014 as a DLC, seventh being I Kissed a Girl in Just Dance 2014, eighth being Roar also as Just Dance 2014 free DLC, the ninth being Waking Up in Vegas as a Just Dance 2014 Popchips exclusive and the eleventh being Dark Horse in Just Dance 2015.
 * It's also Katy Perry's first disco song.
 * The dancer looks like an avatar from Just Dance Wii.
 * They use a move from Pound The Alarm at some moments.
 * "Birthday" in "birthday suit" wasn't censored, even though it was in The Lazy Song, despite the fact that a birthday suit refers to nudity. It may not have been censored because the dancer points to her clothes as is it was a Birthday Suit.
 * The dancer's face can be seen clearly.
 * The dancer smiles a lot, akin to Take on Me and Price Tag.
 * Just Dance 2015 came out in October, which is the same month as Katy Perry's birthday (Oct 25). The fact that this song by her is birthday themed will be featured makes it a huge coincidence. Not only this, but the game also comes out just days before her birthday (either on October 21st or 23rd).
 * Unlike other dancers with makeup that is hardly visible in game, this dancer's makeup is clearly visible.
 * She might be the same dancer as P2 from Nitro Bot.
 * The dancer looks like a clown because of her make-up and costume.
 * Birthday has a move similar to Primadonna. The move is that both coaches turn to each of their sides and "blow" the candles or chandeliers respectively.
 * This dancer's makeup scheme makes her face very visible, which is also happened to Break Free, Price Tag and Take On Me.
 * Her skirt sometimes gets in the way.
 * There is a brief glitch in the track's party master mode (Only in Wii U), if you select the caption "Feel Bollywood" at some point, the coach isn't synced up with the pictograms, in the video you can watch the glitch starting at 0:09
 * The dancer lip syncs "Happy Birthday" every time "Happy Birthday" is sung.
 * Some files for this dance was found in the Just Dance Now Application.
 * The mash-up for this song only contains other songs by Katy Perry. The dancers for all the songs by Katy Perry, except Roar, are featured in the mashup.
 * This is the first time a dancer from any non-Solo mode (in this case, a Trio) is used as a Solo dancer (the Dark Horse lead dancer).
 * Also, this is currently the only JD2015 MashUp that features at least one dancer from every game of the main series.
 * Her avatar was supposed to have red lipstick, but it wasn't added in the final version. Instead, the avatar's mouth is a red outline.
 * The first time Hot N Cold appears in the Mashup, the transition is not smooth like in other mashups, but rather, it seems sudden.
 * There was a VIP on the World Dance Floor named Aurélie during most of November. Players could dance with her while this song was played on the World Dance Floor.
 * "Till" is incorrectly shown as "Til",