Continuity: The Enterprise looks way more damaged than it did at the end of II.

Visible crew/equipment: In the scene where the Enterprise is exploding, a Klingon is shown flying over the helm. When he lands, a person's arm can be seen on the right side of the screen, trying to grab his foot. (Time)

Revealing: When Kirk and Kruge are fighting, a piece of the cliff breaks away and wiggles down the side of the cliff rather than falling like a rock.

Continuity: Early in the film when a lifeform was detected in Mr Spock's quarters, you see a blip on the screen inside the old Enterprise, not the new Enterprise, which was almost a complete rebuild, with a very different layout. Notice the outline of the ship - different engines.

Continuity: When Kirk checks the video logs to find the keeper of Spock's katra, the timestamp reveals that Spock melded with McCoy on stardate 8128.78. The Wrath of Khan begins on stardate 8130.3.

Continuity: In the scene early in the movie where Kirk is talking to Sarek the guns on the wall are suddenly rearranged.

Factual error: According to "The Doomsday Machine", full impulse drive is one-quarter the speed of light. In the first two movies, Enterprise used thrusters as opposed to impulse drive to leave Spacedock, confirming the notion that impulse drive is far too fast to leave such a (comparatively) small structure. Styles, however, orders Excelsior to one-quarter impulse, which is 18,750 km/s. In one second, she will travel half again Earth's diameter. From the time he gives the order to the time we see Excelsior clear spacedock's doors is approximately 40 seconds. Even allowing 30 seconds to go from rest to one quarter impulse, spacedock must be 13-15 times bigger than Earth! That's some serious engineering. Submitted by Grumpy Scot

Revealing: When Kirk enters Spock's corridors at the beginning of the movie, he hears Spock's voice calling out to him from a darkened area. As he walks into Spock's corridors, pay attention to the top right area of the screen. You'll notice the top of the walls and no ceiling. That lets you know that they were filming on a sound stage in a set with no ceiling.

Revealing: Obvious stunt double for Kruge during the fight with Kirk.

Revealing: When the Enterprise explodes, some of the debris briefly turns transparent. (Time)