Revealing mistake: When the guys are driving down the road, you can see Michael isn't under the truck. Yet 2 minutes later, he climbs in the bed. (01:16:25 - 01:18:10)
Revealing mistake: Any time when the two girls are in hell's corridors and running around, you see these corridors as stone walls, yet whenever they back up against one of these walls, you can clearly see they are merely rubber sheeting overlayed on a framework as the rubber sheeting bends and contracts very clearly.
Revealing mistake: During the big fight scene, you can tell easily that Frank is wearing knee pads (try looking when his pant leg is wet). Construction workers will often wear knee pads for work but most often they wear them on the outside of the pants to save the knees of their pants. (00:58:50)
Revealing mistake: After her brother's death, there is a scene in which Alice starts practicing with her brother's nun-chuks. They never show the real actress doing the tricks; instead, they cut to an angle from behind her and show a double who has darker, shorter hair than the real actress and is a bit bigger. (00:56:45)
Revealing mistake: As Reg fights with one of the baddies with the chainsaws, as the baddie take a swing with the chainsaw he misses and cuts into the wooden door. You can clearly see that a vertical cut has already been made in the wood though, to help the chainsaw get in and cut. (01:17:55)
Revealing mistake: When you see Jane pinned dead to the tree you can see her pulse. (00:19:15)
Revealing mistake: In the last scene of the film where the Reverend is holding up the glass jar with the mini-blob in it, you can see the mechanism being used to move the blob (look between the Reverend's fingers). (01:30:30)
Revealing mistake: When Chucky follows Andy home and drops from the chimney and kicks the cover off, its obvious that this isn't Chucky and its a real person dressed as Chucky.
Revealing mistake: When Carol Anne has been hypnotized by the shrink, a hand breaks through the desk and throws a coffee mug through the mirror. You can briefly see the reflection of the plexi-glass protecting the actors behind the mirror as the mirror breaks.
Revealing mistake: None of the grenades Nick throws at the bar does any damage.
Revealing mistake: The dead cop can be clearly seen sitting up even though he's dead as the lady cop tosses the chair through a window. The next shot he's back to being dead again. (01:16:00 - 01:17:15)
Revealing mistake: When the kid who breaks the egg throws it out the window, the egg hits another egg which starts rolling down. You can see the tracks on the grass making it easier for the egg to roll. (00:30:05)
Revealing mistake: When the blade swings down into the side of Mako's face, the blood flows down from the top of the blade, and not from her face.
Revealing mistake: When being chased by her uncle Elvira's hair moves in a way which indicates it's a wig.
Revealing mistake: When they are observing the waxwork figures, it's obvious they are real people just trying to stand still, as you can easily notice the "wax" figures slightly rocking or moving, or the props they are holding doing the same.
Revealing mistake: After Joey and Ed leave the mausoleum, they discover the graveyard full of zombies. As one zombie staggers forward, near the front of the screen, he bumps a tomb and it wobbles. (00:27:25)
Revealing mistake: In the bathroom scene when Debbie is attacked by the clowns from the medicine cabinet, you can see the holes where the puppets are being controlled from.
Revealing mistake: Toward the end film when the female counselor finds Uncle John dead and a camper hanging, the hanging camper's eyes are shaking as he's trying to keep them open in a certain way.
Revealing mistake: When one character's killed, stomach sliced open, you can see the wire yanking open the prop stomach to the left of the camera.