Revealing mistake: Not long into the film when Billy wakes up to find the dog tied up in Christmas lights it's obviously a fake dog, when the camera view is onto the front of the house. (00:29:05)
Continuity mistake: Soon after the Gremlins hatch from their cocoons, Billy goes to the school to check on the professor. When he walks into the classroom, he leaves the door open. Later, when he leaves the classroom, he has to open the door again. (00:49:20 - 00:50:30)
Other mistake: Stripe manages to get the TVs and video camera working in the department store even though Kate hadn't turned the power on yet.
Factual error: For a movie supposedly set in late December in a Northern state, all of the deciduous trees still have leaves on them. The most obvious place to see this is in the opening scene, when Billy is trying to start his car in front of his house. (00:07:05)
Continuity mistake: When the old man is leaving the family's home, in the indoors shot as he turns to walk out the front door, he is holding Gizmo's box under his right arm, and has the "smokeless ashtray" in his left hand. Cut to the outside shot of him walking through the door, and he is suddenly holding the Mogwai box by it's handle, and has nothing in his left hand. (01:42:00)
Continuity mistake: When Billy puts the santa hat on Gizmo, in the first shot the hat is folded backwards so that the bobbled end is hanging behind the hat. In the next shot it hangs over the front of the hat. (00:19:45)
Continuity mistake: A pair of baseballs and several cans appear behind Billy when Stripe attacks him with a chainsaw. (01:32:35)
Visible crew/equipment: Before Billy's mum pushes the gremlin into the microwave, you can see the top of a crew member's head, on the left of the gremlin, next to the microwave.
Continuity mistake: When Mrs. Deagle is killed by the gremlins, throughout the scene she appears to be either bare legged or wearing beige-colored tights. However, when her corpse is on the ground after being launched out of the house, suddenly she's wearing dark blue tights.
Factual error: Gizmo could not drive the Barbie car because it's controlled by remote control.
Continuity mistake: One of the mutated Gremlins scratches Billy's hand and then grabs an apple. On the desk there is a fake brain. In between shots it goes from being on its side to sitting flat.
Other mistake: In the bar, one Gremlin is changing the music selection on the radio. However, the tuning knob is on the right side, out of his reach, the tuner doesn't move, but the music style changes.
Continuity mistake: This is in the scene near the beginning of the movie at the bar where Billy's girlfriend works. Billy is sitting at a table drawing. He is joined by the Vice President of the bank he works at. He sits down and starts talking to Billy. Billy looks up at him while he's talking. Then in the next shot, which shows them both, Billy is looking down at his drawing as if he weren't even paying attention. (00:14:10)
Continuity mistake: In the dark classroom, Billy grabs for the phone, but the Gremlin grabs him. Billy then backs away. We then see the Gremlin reach for an apple which is sitting next to the phone. But the apple wasn't there in the previous shot. (00:47:40)
Plot hole: The whole film is basically told as a flashback from Rand Peltzer's point of view. Now he might be able to talk about things that Billy, his mom, or Kate might have told him, but he wouldn't have known about all the other the gremlins did to the rest of the town like killing Mrs. Deagle, the cops, or the gremlin in the mailbox.
Continuity mistake: When Billy turns to Kate, because she says "Now I have another reason to hate Christmas", he is holding a flashlight up by his chest, yet when the shot changes he is holding it down much lower. (01:15:45)
Audio problem: When Kate is behind the bar, and the Gremlins are drinking beer and smoking, Kate says "Just don't bite me." Her mouth doesn't move at all when this is heard. (01:11:00)
Other mistake: When the gremlin is using live wires to manipulate the traffic lights, the smoke goes in reverse, indicating a reverse footage shot. (01:05:55)
Continuity mistake: When Billy is teaching music to Gizmo and the dog is laying on the bed, the wrinkle on the blanket next to the dog disappears between shots.
Audio problem: When Billy is playing on the keyboard with Gizmo, the second key we see him hit should have been a higher tone, not lower, as it's toward the right end of the keyboard.
Chosen answer: The precise cut-off point is never stated - I've generally assumed that the embargo on feeding finishes once the sun comes up.
Tailkinker ★