This movie is just a cheap knock-off of Carrie.
Seriously. If I wanted to watch a high school chick flick about getting murderous revenge on the popular kids and being misunderstood by the staff as well as the parents, done in a much better and more interesting way, I would watch Carrie, which already came out thirteen years earlier.
I don't understand how no one has made the comparison. Yes, Heathers is Black Comedy, while Carrie is Horror, but watching Carrie today it could definitely pass for a Black Comedy.