Continuity: When Gummer and Black Hand Kelly make an agreement, Kelly looks to his left and he isn't holding a glass. When it cuts, he is looking to his right and holding a glass.

Revealing: At the end of the movie, when the last "Graboid" appears, in one or two shots of him retracting back into the ground, you can tell the shots are reversed, as dirt is being sucked down in an unnatural way. It flies up and sort of "implodes" towards the creature.

Other: At the very end, when a man is painting the "F" of the city's new name on the water tower, with white paint, you can see that though the brush is white, and it is touching the surface of the water tower, no paint is left on the surface of the water tower. Nevertheless, the painter continues painting the letter in the next shot, even though no paint is left on the surface.

Plot hole: When Black Hand Kelly arrives you can see Fu Yien throwing a fresh apple to him. Where would they get fresh apples from? We learn later that the supply deliveries have stopped. They are in the middle of the desert so they wouldn't be able to grow them.

Continuity: Right at the end when the last monster is in its hole, we can see a large part of its body. When it cuts only a small part of the monster is sticking out of the ground.

Continuity: As Hiram is leaving Rejection and is stopped by Fu, his horse changes position from about 1 1/2 feet from the bicycle to the side of the road, about 4-5 feet from the bicycle.

Factual error: In the scene where the people of Rejection/Perfection are preparing to fight the Dirt Dragons, Hereim loads the Punt Gun and puts a little gold piece in it (a percussion cap, containing a small amount of gunpowder used to set off the main charge in the barrel). He shoots at the Dragon when it pops up and misses. The next time he loads the gun, he does not replace the percussion cap (which can only be used once), yet he is still able to fire the gun with no problem and kill the Dirt Dragon.

Continuity: When they are talking with Black Hand Kelly, there is a shot where Lord is looking down. When it cuts, she is staring right at Gummer.

Other: This movie is set in 1889. There are clear deep truck wheel tracks on the road when Gummer is about to leave Rejection. The steam tractor's wheels are too wide to make these tracks.