Continuity mistake: When Sarah shouts, "Quick, this way!" and then Sir Didymus shouts, "No, not that way!" the hanging sign with the hammer hangs crookedly by only one chain. However, two shots later when Sir Didymus shouts, "You're going the wrong way!" the sign hangs properly from two chains. Then later, when the three Samurai Goblins jump in front of Sarah and the rest, the sign's chain is broken once again. (01:20:00 - 01:25:40)
Continuity mistake: When Fievel discovers that Warren T. Rat is actually a cat in disguise, the hat tucked into his black belt disappears between shots. (00:51:20)