https://www.theodysseyonline.com/nine-eras-disney-animation
What we know as the ‘Golden Age’ of Disney animation was kick-started with the introduction of Snow White and the Seven Dwarves, the first full-length animated film; a film which solidified the legitimacy and potential of the animated medium.
Throughout the short period of this era, several classic full-length films were produced, such as Bambi, Pinocchio, Fantasia, and Dumbo. These films showcased flowing traditional animation with hand-painted backgrounds, a technical combo that would be favoured in many more animated features throughout the later ‘Silver Age’ of the 1950’s and 60’s such as Cinderella and Alice in Wonderland. Even as hand-drawn animation began to shift into digital production with computer-generated backgrounds such as in Beauty and the Beast, they continue to emulate the look and feel of painted backdrops the Golden Age.
Bambi is an example of an early full-length animated feature where the protagonist is an animal rather than a human, certainly a challenging choice, even just considering it from solely an animation standpoint. The character needs to have a variety of gestural expression as well as the ability to express emotion facially in a way that the human viewers of the film will understand. Over time, the depiction of animal characters in Disney films split, with The Lion King maintaining the more animal-like movement in the characters as shown in Bambi, and the recent film Zootopia making the animal characters more anthropomorphic by walking bipedally, wearing clothes, etc.
Another theme that Golden Age Disney animation pioneered is the adaptation of fairy tales and fantastical literature into features such as Pinocchio and Alice in Wonderland. Many classic fairy tales (especially Grimm stories) retain many darker themes and aspects in the story, and Golden Age films did not appear too shy to include the death of characters (particularly villains, such as in Snow White, Sleeping Beauty, etc.
Throughout the last century of animation production, other studios have adopted many of the techniques, styles, and themes put forth by Disney Studios, assuring its ability to set trends in traditional animation.
Animation: Critical Perspectives 