During the biometric scan that the seven marauders undergo, the sound effect is the same as that emitted by the Flying Machines in the original The War of the Worlds (1953).
The Marauder armored combat suits and the "Q-Bomb" (originally called the "Nova Bomb") are the main elements drawn from Robert Heinlein's original novel in this film. Many fans were disappointed that the former did not appear in the first Starship Troopers film.
Both Sky Marshal Phid and Anoke wear the incorrect epaulets. The epaulets they are wearing are of the Rank of Lieutenant not Sky Marshal. Zander Barcalow, a Lieutenant in the first film, wears the same epaulets.
Why doesn't anyone else from the first film (Carmen, Carl, Ace or Zim) appear in this film?
A
The actors were most likely unavailable and/or did not want to do this film. In context of the film, their characters are either across the galaxy or are dead.