If you forget that this is the continuation of two very successful franchises, and consider this as a graphic novel adaptation, then it is actually a bit more successful than people give it credit for.
In tone and spirit, this is much more of a Predator movie than an Alien movie - it is as an Alien movie this most disappoints. However, as Predator movie I would suggest this is better than Predator 2 was.
The plot is set in modern time, when a heat signature revealing a hidden pyramid under the ice is seen by satellite. The owner of the satellite, played by Lance Henrikson, brings together a team of archaeologists, biologists and `security' (the equivalent of Star Trek redshirts I guess) to investigate. What they find is a pyramid used by Predators to hunt the ultimate prey - the Alien.
The rest of the story is just bunkum, and don't think too hard about many of the continuity points because much of it does not quite work, but the action scenes are handled adequately, mostly by pilfering ideas from the previous movies and reproducing them in watered down form for characters we have not yet come to care about. Best original (-ish) idea was that the pyramid reconfigures every 10 minutes once activated, to add spice to the hunt and help split our characters up to be picked off one at a time.
Saana Lathan is no Sigourney Weaver, but a stronger character than one might expect from Paul W. S. Anderson (who also directed Mortal Kombat). Nice to see Colin Salmon, the English actor of several Brosnan era Bond movies, in another role - shame it wasn't in a better movie.
Overall, this is not a disaster as a movie given its rushed production and low bdget - but don't go in with any expectations of anything approaching even the worst of the Alien movies. Think of it as a so-so Predator sequel and you get the idea.
3 ½ stars - I'll opt for 3, because of the corny script at times.