Revealing mistake: When Howard's running from the female bikers, Satan's Sluts, look closely at one and you can tell it's a guy in drag, one wearing a dark blond wig. (00:10:00)
Suggested correction: I was in this part of the movie, everyone in this scene (except for the duck) is female.
Revealing mistake: During the ultralight chase, a police car drives up a hill and overturns. The metal plank underneath to allow for the stunt is visible.
Revealing mistake: When the microlight is about to fall into the lake next to the lab, Howard's POV shows a straight road ahead. However, a shot later the microlight rises from an obvious ramp hidden between bushes which results in a more comedic crash.
Revealing mistake: When Howard climbs up a truck and fires the blast that destroys the laser, he is replaced by an obvious doll, not only does he not move an inch, but when the truck shakes he wobbles as if he was nailed to it.
Revealing mistake: When the Overlord extends his arm outside the truck, lights up and electrocutes a cop the shadow that his arm casts is not real, but FX made. Problem is, his arm does not cast any shadow on the truck for a couple of shots.
Suggested correction: Again, watching the movie right now. His arm is indeed shown as a reflection.
Revealing mistake: When the Overlord is driving the truck and a monster tongue comes out of his mouth he is replaced for a very cheap and blatant wax figure with fake skin and fluffy hair.
Revealing mistake: When the Overlord sends Howard flying and makes him turn around on air the shadow of the pole moving him is visible.
Revealing mistake: When Jenning/Overlord sends a man flying through the window, the cable attached to his back is perfectly visible.
Revealing mistake: Before the car pulls up by the diner, after smashing a billboard, skidmarks from previous takes are visible on the ground.
Revealing mistake: After Howard in the flying chair passes by the elevator and zooms through the hallway he becomes violet due to the blue screen effect.
Revealing mistake: When Howard's chair is launched backwards, right before he crashes through the toilet room check for the black metal object underneath the chair where the mechanism to move the chair is.
Revealing mistake: Before Howard's chair is launched backwards everything appears to be shaking but check the coat hanger behind and the stuff on the floor and they remain still revealing the camera trick.
Revealing mistake: When Overlord moves the chairs and tables to block the door, the strings used to move them are visible.
Revealing mistake: When Howard enters Earth and falls through a ceiling the safety cable attached to him is briefly seen.
Revealing mistake: When Howard's couch starts to shake the ashtray and table on his left don't move an inch.
Revealing mistake: Very obvious ramp hidden behind the stall to allow for the cop car to jump.
Revealing mistake: When the microlight is flying, Tim Robbins' stunt is very noticeable.
Revealing mistake: When they're riding with Jones look closely in some shots and you'll see Lea Thompson's stunt double.