Continuity: The Doctor's shoes are different at the beginning of this story compared to the ones at the end of the last story.

Visible crew/equipment: In episode 1, when Monarch tries to open the TARDIS, you can see the head of a crewmember hiding behind a crate in the foreground.

Factual error: There are currently well over 700 different native Australian languages, and undoubtedly many more have been extinct for centuries. The chances of a 20th Century European-Australian such as Teegan being able to understand a native Australian language from around 35,000 years ago are so astronomical it is beyond belief.

Factual error: In episode 2, the policemen from 1925 recognise the TARDIS as a police call box, even though TARDIS-style police boxes weren't introduced until four years later, in 1929.

Audio problem: In episode two, the Cyberleader misses a button on his console, yet we still hear a beep...

Visible crew/equipment: As Lieutenant Scott is moving up the scaffold staircase, you can see someone at the top of the screen reading a script.

Other: In episode 4, as the Doctor, Tegan and Nyssa are being led away from the bridge, the Cyberleader loses his footing when he gets to the bottom step, and stumbles/trips up (He recovers himself very quickly; so quickly in fact, that this mistake was left in the finished episode).

Continuity: The hole that the cybermen make in the door increases in size just before they step through it.

Plot hole: The freighter traveling back in time makes no sense. According to Adric, the Cybermen's computer is responsible, yet the Cybermen possess no such technology; their machine's task was simply to navigate the freighter towards Earth. The idea that time travel could happen by accident is also absurd.

Plot hole: The Cyber Leader states that he needs the Doctor to pilot the TARDIS. It makes no sense then, that he would try to kill the Doctor once inside, and before the TARDIS had landed in a safe place.

Revealing: When Lieutenant Scott kills the second Cyberman on the bridge, he starts falling down way too early.

Revealing: When the Cybermen break through to the bridge, they brush against the door and it bends as if made of cardboard. It was supposed to be made of reinforced steel.

Continuity: The mouth panel of the Cybermen costumes was originally intended to be a clear perspex panel. During filming, it was felt that this showed too much of the actor inside the Cyberman costumes. So a decision was taking - mid way though filming - to paint over the 'clear' panel with silver paint. However, this does result in the mouth panels of every Cyberman alternating from 'clear' to 'silver' from shot to shot.

Factual error: The Cybermen sets four explosive charges around the outside of the door, yet only the middle part of the door is damaged...

Factual error: As the spaceship approaches the Earth of 65 million years ago, the Earth looks very much like the present day one. Hasn't anyone heard of "continental drift"? The Earth's land masses of 65 million years ago were not where they are now. (This has been fixed on the DVD)

Continuity: In episode four, as they approach the TARDIS, the female member of the remaining troopers is grabbed and doesn't make it inside. But when the troopers do get inside the TARDIS, it's a man that's missing.

Revealing: During the "cliffhanger ending" at the end of episode 3, it's blatantly obvious that the three columns of advancing Cybermen are merely mirror images of each other. The head of each column has black head bars indicating leadership, and is holding his gun in exactly the same position.

Plot hole: Although the Cybermen view a clip of the second Doctor - taken from "The Wheel in Space" - the Cybermen refer to it as if it is taken from "Tomb of the Cybermen, a completely different Doctor Who/Cybermen story.

Revealing: The "dead" crewmembers at the end of episode two can be seen breathing.

Revealing: Just before the Cyberman fires on the console, you can see Adric trying to keep as far away from it as possible before it explodes.