The "normal" humans are the least appealing. *mild, brief spoilerdity*

As is the case in much of life, the "normal" human characters in this movie are the least appealing.

Donald Pleasence and Tom Baker are both good actors and make their characters interesting, and even appealing.
Michael Dunn is always good and while most of the freaks were obviously inexperienced actors, they were still much more appealing than the normal human students who were filling the typical protagonist preyed-upon roles.

Even when the "normal" humans became plant beasts, they were more interesting and appealing than when they had more humanity about them.

It is usually true, but there are few movies that reveal such a realistic level of normal human unappealingness.

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