Continuity mistake: The books and other items on the desk of the boy sitting behind Andy move about between shots, and the boys sleeves change from rolled up his arms to pulled down to the wrists too. (00:33:00)
Revealing mistake: In the scene where Dr. Ross Jennings is trapped in the corner of the cellar, you can see that the tarantula which starts climbing up his leg has a huge black stick stuck to the back of its body, pushing it along. (01:36:05)
Visible crew/equipment: Near the beginning of the film when the police car explodes and flips over, you can blatantly see stunt wires used to aid in flipping the car. (00:02:45)
Revealing mistake: The Gremlin who throws the beaker full of acid has his arm operated by a stick, which is visible as he chucks the beaker. (01:08:05)
Visible crew/equipment: Look over Val's right shoulder as Rhonda is supposedly driving upside down with her legs sticking out the back window of the truck cab and you can see a man driving for her. (00:42:40)
Visible crew/equipment: When Darkman swings on the wire to save Julie, you can see a large wire coming out of his shirt to support his weight, and you can make out several large wires holding Julie in the shot of her being grabbed.
Continuity mistake: As the police are seen prepping for battle, and Eigerman is delivering the line "Whether it be freaks, commies or third-world y-chromosome mutants we are there - the sons of the free", watch his hands as he picks up the large gun. As the camera cuts during the dialog, his hands have suddenly swapped positions on the gun.