While very low-budget, this is still a pretty enjoyable simple horror film. A gawky, geeky high school student gets bullied by his teachers and classmates. He gets revenge.
How he gets revenge is foreshadowed by the fact that the movie begins during an English class in which the teacher has finished showing the first half of a Dr. Jekyll and Mr. Hyde movie. Twisted Brain is itself a sort of Jekyll and Hyde remake. The student accidentally handed in a biology report instead of his paper on Stevenson, and the teacher gives him an F on the Stevenson report, and chops his biology paper up with her paper cutter. Those old paper cutters are like machetes! Turns out the student was working on a potion to change the physical strength of living creatures. After his guinea pig kills the janitor's cat, the janitor forces him to drink the potion for some reason, and there's conveniently a barrel of acid in the lab....
Meanwhile, he finds he's less shy in his normal form and starts warming up to a girl he had a crush on. Like Jekyll, the potion also starts trying to change him even when he hasn't drunk it.
I watched it on one of the DVDs in Rhino's Horrible Horrors Vol. 1 box set. It's not horrible, just cheap. Apart from the gore scenes, it almost feels like a Saturday morning TV movie. It's too bad there's not a commentary track.
