Kevin J. O'Connor added the line where he asks if a person can "suddenly get asthma "
This film went over a year in post-production because it took a while to figure out how to do the various special effects for the monsters.
Kevin O'Connor wore pads for the scene where the mercenaries take turns hitting and kicking him, but at the end of the shooting day he was covered in bruises. "I felt so horrible," said Stephen Sommers.
Sommers is grateful for people buying the Blu-ray as watching it edited on TV comes with nearly thirty minutes trimmed to allow for commercials. "It's good for my pocketbook, but it makes me cry sometimes."
Claire Forlani was cast as Trillian St. James. She even started shooting, but walked out after just three days, due to creative differences with director Stephen Sommers. The part subsequently went to Famke Janssen.