It was also the first full length cel-animated film. Walt Disney's first animated short, which was 6 minutes long, was Little Red Riding Hood in 1922. Walt Disney's first feature length film was Snow White and the Seven Dwarfs, released on December 21, 1937. It was also the first full length cel-animated film. Walt Disney's first animated short, which was 6 minutes long, was Little Red Riding Hood in 1922.