Revealing mistake: During the final battle in hell, when the army of Spawns rise up, there are some small errors to look for. First, during a few shots where the army is closer to camera, you can see the CGI army becoming "pixely." Also, you can see at least one of the Spawn floating in the air, not standing on the platform with the rest of him. Problems with the CGI rendering/animation.
Revealing mistake: In the scene, when the bug (actually another Kothoga monster) run out from the box that Margo has opened due to strange noises, there are visible wheels from the puppet of the bug. (00:48:40)
Revealing mistake: Whilst Rumi is speaking with the producer about Mima, a man comes into the room to talk about how the new CHAM is coming along. When the man stops walking to take out a magazine and places it on the table, it can be noticed that, due to an animation error, his legs pass in front of a coffee cup on the table. (00:24:18)
Revealing mistake: When Magoo is skiing downhill, and the camera points directly at him whilst skiing, if you look to either side of his skis, you can see the tyre tracks of the vehicle towing him.
Revealing mistake: In the basement shootout, when a man is shot in the stomach, we see a close-up of his guts hanging out, and there's tape around it.
Revealing mistake: After the Djinn escapes and there's an explosion in the lab, you can see some stuff on the ground that looks like it's on fire. The objects are not actually burning, the fire is being produced by a burner. There's no smoke from the objects, which is a dead giveaway that they're not actually "on fire." (00:18:15)
Revealing mistake: At the end of the movie when Dusan sets the bomb for a time to blow up, he also sets his wristwatch, but if you look closely at the watch, he hasn't set it to a timer/stopwatch. (01:31:15)
Revealing mistake: When Mr. Eddy is shot in the head and killed, there is an extremely quick shot that you can catch of what is a puppet's head exploding from the shot, before it cuts to Mr. Eddy falling back dead.
Revealing mistake: When Brad and Caroline are running off in the taxi, across the border to PA, it is obvious that the lighting inside the cab are studio lights from the traveling crew, as natural moonlight would not reflect so strongly inside or out of the cab, at that speed.
Revealing mistake: At the very beginning of the film, we see the transfer vehicle carrying Jack driving down the road. You can tell in several shots that the (fake) snow isn't really falling, but is just being blown in front of the camera from off-screen, especially since there's no snow hitting the road, and it's coming from the side, not above.
Revealing mistake: During the fighting scene outside the general store, Taggart hits one of the bad guys square on the nose two different times. After the second time, when the man is lying on the ground saying "Oh, my nose!", his hand's supposed to be holding his nose in pain but instead his hand is up around his forehead instead (his arm sort of blocks this but you can still see it).
Revealing mistake: It's obvious the snow is fake. You can see when Alex runs outside in his pajamas.
Revealing mistake: In the locker of the Gentleman Caller there are multiple newspaper clippings. When Cross looks at the one talking about his niece, it just does not talk about his niece. The clipping is on camera long enough to be able to read without freeze frame, and it's talking about things like police brutality and apartheid (actual word used), entirely unrelated to the fake headline and picture caption. (01:18:00)