It is the first film of the Species franchise that does not feature Natasha Henstridge, who played Sil in the first film as well as Eve in the two previous movies (Even though her role in Species III was a small cameo).
The producers wanted to go back to H.R. Giger's designs of the alien creature due to popularity with fans and the absence of this decision in Species III (2004). The original look is apparent but with different color variations and new spikes on the aliens' wrists of the nemesis. It is also a first in the series that a half human-half alien character does not change fully into the alien creature but has prosthetic eyebrows, veins and contacts for a long period of time in more than one scene.
A new ingredient for this fourth film is that the protagonist doesn't know she is half alien. Miranda's re-birth halfway though the film proved different as past versions have begun with the characters as a child before making their chrysalis in the first and third films. The story begins with Miranda as a young woman, not a little girl like Sil in the first film, or Sara in the third film.