Sleeping Beauty was made in 1959 also set in a French kingdom and was the last fairytale Walt Disney produced. Something that separates this movie from the first two is that it is not a Grimm Brothers fairytale which could give answer to some of the differences.
Also there is quite a divide between the first three movies and the later four. In Sleeping Beauty and the other two the female character was very meek, and always the fair beauty, later on things take a very different approach.
After watching this movie I think it is the harshest princess movie so far. Maleficent has so much spite for Princess Aurora that is simply based on not being invited to her christening which is unlike the other two movies where their hatred is based on jealousy for the Princess' good looks.
Not only does the hate seem unfairly based but also takes up the majority of the movie. Most of this movie is focused around defeating the evil. The main character, "Princess Aurora...appears for fewer than eighteen minutes in the film" - Wikipedia.
Also the darkness of the character Maleficent adds to the overall scare factor. Not only does this character hide in the shadows and appear from a fog, but she also changes into a huge fire-breathing dragon that the prince has to defeat. With so much of the movie focused on this intense amount of the evil force I give this movie six fairies out of ten.