Continuity mistake: When he is in the aquarium tank (just after he says "I've got to, mister!"), he leans down with his glasses in his left hand. He's supporting his weight on his hands so can't move them, but in the next shot from behind his left hand's flat on the ground with no glasses in sight. (00:16:10)
Continuity mistake: In the scene where Ace is trying to figure out the Finkle/Einhorn connection there is, what looks like, an air horn on the far end of the table to the right of the dog. A shot or two later when it shows the dog's hair around the picture of Finkle you can see the end of the horn laying right next to the dog on his left side.(This is visible in the screen shot already on the site that shows the dogs hair position changing.).
Continuity mistake: When the people take the dolphin and put it in the truck near the beginning, they close the truck door and the door is red. When it shows the truck driving away, the door is white. (00:07:15)