The idea behind the plot is good, but as most of the concept is borrowed from Alien, and Giger obviously didn't work too hard on an original idea, it makes it to the end of the train journey before you spot the cliches, and the blatent copying. Which covers the first twenty minutes.
Woefully miscast, with Marg Helgenberger essentially doing what she now does in CSI, Alfred Molina seriously out of place, and Forest Whitaker being ignored most of the time, when you can see he's right.
Since the entire plot consists of the foursome trying to track the alien, getting picked off one by one and eventually burning it, not forgetting the unnoticed baby with the reptilian tongue, its a small wonder that this one was allowed to escape the storyboard, where someone should have spotted it - "uh, guys, this looks awfully like Alien in earth - should we start over on it?".
I only give it two stars for the incredibly funny sex scene with Molina - "this doesn't usually happen to me".