Corrected entry: About half-way through the film, there is a montage of the captives climbing through various cube doors. Part of that montage shows them emerging from the floor, which should be impossible, as the cube cells are a good 15 feet tall. There is no evidence or indication that gravity changes direction in any of the Cube movies, so emerging from the floor should be impossible.
Corrected entry: In end the scene where Kate has just escaped the Hypercube, we see a big puddle of water in a huge warehouse - the technicians pull her towards the dry cement and a commanding officer. When she gets there, she starts talking to the commanding officer - notice in the shots that show Kate, there is no water in the background. (01:28:14)
Corrected entry: In the middle of the film, as the group is moving from cube to cube, the blond woman's outer shirt mysteriously disappears and reappears. In one shot, she is wearing a white button-up shirt over a white tee shirt, then she is wearing only the white tee shirt with no sign of the button-up shirt, and then she is back in both shirts again.
Corrected entry: Jerry is comparing his watch with the one that is found in the cube. These watches should be exactly identical, but have different serial numbers. (00:36:00)
Corrected entry: When Kate escapes from the hypercube and is picked up out of the water by the two soldiers, there is no liquid or evidence of wetness on her back. This is because the "water" was entirely computer-generated. (01:23:55)