Continuity mistake: In the first scene, the old alien man comes to pick up his spaceship and Ratchet instructs him to "Now, let's fire up that mag booster." The old alien pushes the switch forward to start the mag booster. Later in the movie, Ratchet flips the switch backwards to "engage mag booster" as Clank commands. (00:06:30 - 00:26:30)
Continuity mistake: When Batman and Batgirl are about to have sex on the roof, Batman lets his left hand slip down from her back to her butt. In the next shot, it's on her back again.
Continuity mistake: In a second view at a different angle of the bank employee being shot, one of the doors that was shattered in the original shot is not shattered in the second shot. (00:03:02)
Continuity mistake: At the beginning of the movie, the hunter is looking for his dog. The rifle on his shoulder keeps changing position, being upside down or not - which is easy to spot because of the big scope. (00:01:30)
Revealing mistake: Despite Sigourney Weaver supposedly having had her fingers cut off if you watch her when she's in her straitjacket you can see her fingers moving around.
Continuity mistake: While Jax is held against the wall by two of the Furies it shows her bare feet held off the ground. As she moves across to Sinbad after he plunges the sword into the third Fury she is wearing flip-flops. (00:29:17 - 00:29:54)