Continuity mistake: When Big Bob throws a model of Arnold's house in the trash it lying on its back but when it shows it again it is standing up straight.
Continuity mistake: There's a scene where Arnold is talking about saving the neighbourhood, while Helga is on the roof of a building talking to herself. Arnold is in the street, and there's a man in a white tank top standing in front of him. In another shot, the man is standing behind Arnold, and Helga shoots a plunger at his head. Then in the next shot, the man is back in front of Arnold and his head doesn't have the plunger on it anymore.
Continuity mistake: In one scene Grandpa packs up all of Arnold's stuff, but in the scene when Arnold and Gerold have a sleepover all of Arnold's stuff is back in his room.
