Although the fact that the Cybermen are seeking "revenge" is often cited as a goof, in fact it is Tyrum who says they need fear the "vengeance of the Cybermen." The Cybermen simply plan to destroy Voga as a primary threat to their conquest.
Despite the fact that Cybermen are emotionless beings, the Doctor easily provokes the Cyberleader into strangling him. Worse, the Cyberleader then tosses him away.
In the previous episode the Doctor explains the Cybermen's weakness to gold is because it clogs their breathing appartus. But here gold affects the Cybermen radar. Radar doesn't need to breathe.
The Vogans live on a planet made of gold. They helped develop the gold weapons that defeated the Cybermen. They know the Cybermen are coming and live in a state of paranoia about that eventuality. So why in the world do they attack the Cybermen with useless projectile weapons instead of "glitter guns" or some other gold-based weapon?
Cyberleader: The matter is of no interest to you.
The Doctor: Everything's of interest to me.
Cyberleader: That is why we will rule the cosmos!
The Doctor: Loose thinking. The trouble with Cybermen is they have hydraulic muscles, and of course hydraulic brains to go with them.
Lester: Why don't we just wait here?
The Doctor: I think my idea is better.
Lester: What is your idea.
The Doctor: I don't know yet. That's the trouble with ideas – they only come a bit at a time.
The Doctor [who has a bomb strapped to his back]: Careful, careful! I might explode!
The Doctor [to the Cyberleader]: You've no home planet, no influence, nothing! You're just a pathetic bunch of tin soldiers skulking about the galaxy in an ancient spaceship.
There's an amusing sight gag when Lester, the Doctor, and Stevenson are recovering consciousness. Lester is covering his ears, the Doctor his eyes, and Stevenson his mouth. This is an in-joke to the three monkeys and the phrase "Hear no evil, see no evil, speak no evil."