Continuity mistake: When DeVries' Ferrari crashes into the fence, the license plate is lying crooked, touching the bumper. When the cops blow it up, it's not touching the bumper. Also notice that the petrol tank and exhausts have been removed, revealing that the car blows up by explosives rather than police gunfire. (00:07:40)
Visible crew/equipment: When the blob just misses Laverne, you can see a crew member under the raft (probably operating the mechanical special effect).
Continuity mistake: In the scene at the beginning of the movie where the flying vampires are chasing the security guard across the boardwalk parking lot, the positions of his arms as he is running changes back and forth between shots. In the close-ups of the guard's face, his hands are up, holding his hat down on his head. In the wide shots, his arms are down at his side. (00:02:45)
Continuity mistake: When Jamie gets out of her car, her leg warmers reach down to her heels. In the next shot, they've been pulled up to just her ankles. (00:07:05)
Continuity mistake: Early in the movie, Mac throws the dead green berets' dog tags to Dutch. As he catches them, Dutch has his hand closed in a fist, and the dog tags are hanging to the left. But in the close-up shot where we can read the name, his fingers are more open, with the tags resting in his palm.