Irwin Allen Science, plot and special effects
Science: I know there is no point mentioning this, we all know Irwin Allen science is weak but in this film which I have fond memories of... Pacifica had to turn down the lights to increase the warhead megatonnage? I could go on.
Plot: I know there is no point mentioning this, we all know Irwin Allen plots are weak but in this film which I have fond memories of... the vault was supposed to be able to withstand a hit by a planetoid with a density 3 million times that of Earth but Stuart Whitman just walked in through a horizontal Jeffries tube and knocked out an air conditioning grating?
Special effects: There is a point mentioning this since Irwin Allen is known for good effects. The only effects that looked good were the FS stock footage from VTTBOTS. The CBTS and subs looked like a bad models. Irwin Allen liked to use stock footage which is often OK. However, here is was definitely a bad choice. Usually stock footage looks worse than new footage. Not the case here. The use of the VTTBOTS FS stock footage just emphasized how weak the new effects were.
Speaking of density. During the climactic fight the stacks of gold bars actually moved when a body hit them.
I'd have to say an inferior production relative to his TV series.