Factual error: Take a look at the directory listing on Chris' computer. It is absolutely absurd. The game Battlechess, for instance, is shown having the filename BATTLECH.ESS . No popular program uses an .ESS extension. It should be BATTLE.EXE . Besides, Battlechess takes a whole CD by itself. It would not be on a single floppy with a bunch of unrelated files.
Continuity mistake: Towards the end of the movie, when the mob appraiser has verified the medallions are authentic, he is wearing two white gloves. He then asks if he can leave. When he stands up and gathers his things, he has only one glove on. The shot cuts away. When it cuts back to him, he has two gloves on again.
Other mistake: There are several moments while using the clown dummy toy that make it very obvious it is an actor in a suit. Most obvious of which is that it somehow 'senses' things like the momentum and orientation of the person controlling it, when all it is shown to do is copy muscle movements/motor skills. There are far too many examples to list.