Plot hole: Freddy is killed at the end because he sees his own reflection in a mirror, which causes the souls in his body to revolt and kill him. But this weakness to mirrors and reflections doesn't fit in any other film of the series. He repeatedly appears in mirrors in the other films, and in the climax of "Dream Warriors," he even appears in a hallway of mirrors that are facing each other, where he would have seen his own reflection multiple times. No matter how you slice it, his death in this movie doesn't add up in the overall context of the series.
Suggested correction: It's implied that it's not looking in the mirror that kills Freddy, but some extension of Alice's Dream Master powers. Both her and Freddy's powers have been changing and fluctuating throughout the film. It's not really explained, but it doesn't contradict previous films.
