My word, I never realised it could be so bad... There is just nothing to recommend this film. The Predator itself is a totally redundant character in this film, despite having the only tangible narrative, he feels entirely tacked on. The conclusion only serving to emphasise his lack of relevance. If the Predators' involvement had just been left as a means for the Aliens to get to Earth, it would have acceptable.
The Strause brothers also alter the film's mythology wantonly. The life cycle of the Aliens accelerated to the point of comedy, removing any dramatic weight or threat that they once held, rendering them as merely cannon fodder. The reproductive element of the original is discarded in a particularly distasteful scene with the hybrid "pred-alien" (what's wrong with alien-ator?).
There also appears to be scenes missing, for example, the ones that turn the town into a war zone. One minute there are three Aliens running around, the next we have the National Guard turning up, for a scene that was a blatant rip off from Aliens, and poorly executed.
If only the action was engaging, if only the characters had been passingly interesting, if only there had been one moment of invention, if only his keys hadn't been thrown down the sewer...