I liked the first one. The second one was pretty much just an excuse to show as many boobs as possible. The third one definitely exceeded both the second film and my expectations. Honestly they should have left the story where it was at the end of species three.<br /><br />This movie had almost nothing to do with the first three. None of the same characters and it doesn't explain how the scientists got there hands on the alien DNA. The idea's not bad, but after the first chase scene in the streets of Mexico the movie shifts to a series of dimly-lit night sequences which make it hard to even understand what's going on. <br /><br />And let's be honest here: a large focal point/selling factor for this series is the sexuality that goes along with these reproducing aliens. The nude scenes were pretty pointless in this film. There was enough shown to attempt some arousal but the lighting was so bad that it's hard to make out what's even happening. If they wanted an excuse for nudity they should have lit the stages better. If they wanted to just convey the sexual point in the story they shouldn't have filmed full body sex.<br /><br />Basically if you were happy with how they ended number 3, don't waste your emotions getting involved with these unrelated characters. If you just wanted to see boobs, pick a different movie.<br /><br />Either way steer clear because you'll be disappointed no later than halfway through the film.