* AlternateCharacterInterpretation: The alien species which sent the message with the information to create Sil. Was it all an evil plan to exterminate the human population over the Earth and replace it with Sil's offspring as it looks, or it was a genuinely friendly attempt to share biotechnology which got screwed because Finch and company couldn't handle it the right way?
* BestKnownForTheFanservice: The ''Species'' films are mainly known for one thing: Natasha Hensridge taking her clothes off a lot.
* EvilIsSexy
* FoeYay: One sided, due to Sil's and Eve's natural instinct to mate, she seems to develop a minor attraction to Preston. However Preston sees them both as a monster that has to be destroyed.
* HilariousInHindsight: One of Sil's victims in the first was named John F. Carey. The 2004 Presidential candidate was John F. ''Kerry'', who was a well-known senator at the time of the movie.
* NightmareFuel: Many of the deaths are brutal (such as Sil ripping the spine of a woman), the alien transformations are as disgusting as the ones from ''Alien'', and even [[http://www.youtube.com/watch?v=x4aydQSu7-E the first movie's soundtrack]] contributes to a creepy atmosphere.
* ParanoiaFuel: See FanDisservice.
* {{Sequelitis}}: First film is considered either SoOkayItsAverage or SoBadItsGood. The following ones aren't so lucky. Only the third one has some not too negative reviews.
* SpecialEffectFailure: The aliens prosthetics in ''Species III'' are vastly inferior to what was seen in the two previous films. ''The Awakening'' has similarly bad effects, but for the most part it does a better job of working around them.
** In the first film, the "mist" in the woods outside the hot tub guy's house is patchy, obviously from a smoke machine. Also the ConspicuousCGI in the final scenes (which H.R. Giger complained about, saying that unlike the animatronics they weren't worthy translations of his design).
* StrawmanHasAPoint: Xavier says they made her female assuming she'd be more docile, which is [[YouNeedToGetLaid seen as funny]] by Preston and [[CriticalResearchFailure it's actually untrue]] as female members in Earthly predatory species tend to be more aggressive than males. But by doing so they actually may have bought themselves more time, considering a female only can have one partner and reproduce more or less one by one while a male can have multiple ones at once and impregnate all of them.
* VisualEffectsOfAwesome: There's no denying ''Species II'' had some pretty awesome scenes.