The idea behind most of the film being seen on a radar, with incoming monsters represented by blips on the screen, was inspired by Hewer's love for the films Alien (1979) and Aliens (1986), and the similar scenes that they have.
The characters General Skerritt and Corporal Weaver are named after actor Tom Skerritt and actress Sigourney Weaver, who played Dallas and Ripley respectively in Alien (1979), upon which this film took huge inspiration from.
The sounds of the guns used in the film are as follows: HOTEL - ACR assault rifle; ECHO - Spas-12 shotgun; LIMA - AK47 assault rifle, XD-9 handgun.
The address of the office building in which the film takes place is: Giger Building, 1979 Scott Street. It is named in reference to H. R. Giger, mastermind of the original xenomorph Alien design and 1979 being the year that Alien (1979) was released, which was of course directed by Ridley Scott.
The cat that gets shot in this film is a reference to the cat, Jonesy, that appears in Alien (1979) and again briefly in Aliens (1986).