Elsa (Frozen) of the song "Let It Go", with critics frequently calling her a "powerhouse". Attempts were made as early as 1937 by Walt Disney to adapt Hans Christian Andersen's fairy tale, "The Snow Queen", into a film. The tale focuses on two children, one named Gerda, who served as the basis for Princess Anna, and the other named Kai, who is "cursed with negativity" after his heart is pierced with a shard of glass from an enchanted mirror and is later kidnapped by the Snow Queen. However, Disney struggled with creating a believable, multi-dimensional adaption of the fairy tale's title character,
The Story of Frozen: Making a Disney Animated Classic footage from Norway that inspired the look of "Frozen"; announcements of what is planned for the "Frozen" franchise; a preview of Anna, Elsa, and Kristoff's appearances in the TV series "Once Upon a Time"; and a sneak peek of Walt Disney Animation Studios' film "Big Hero 6". The special also announced "Frozen Fever", an animated short film serving as a sequel to "Frozen", which was released alongside the live-action Walt Disney Pictures film "Cinderella" on March 13, 2015. The Story of Frozen: Making a Disney Animated Classic The Story of Frozen: Making a Disney Animated Classic is a television special