Continuity mistake: When Beer Guy gets his eye ripped out, he bleeds on the blonde girl. When we next see her, prodding the dead body on the billiards table, the blood pattern on her face is very different. (00:38:45 - 00:40:00)
Visible crew/equipment: Near the end, when the monster has crashed through the wall of the bar, the monster rips off his deer skull mask/helmet to show his true face. As soon as he tears the mask/helmet away, look carefully to the right of the screen. For a split second, you can see the black outline of a person standing beside it. (This is revealed in the commentary.)
Continuity mistake: When Beer-Guy gets vomited on by the creature, there are no maggots or bugs on him, only green goo. Yet, seconds later, when he is washing himself off, there are maggots all over his hair and face.
Plot hole: If the creatures are strong enough to simply burst through the walls, as shown at the end of the film, then the creature upstairs should not have been stopped by the small door that Bozo, the bartender and heroine shut on it to stop it. It was one of the larger creatures as well, so it could have easily gotten through.
Continuity mistake: When Tuffy's son is killed, you see his shoe fly by the camera, with his severed foot still inside. Shortly after, when you see the shoe again, it is empty, and simply covered in blood.
