It is a shame that like Blue said, that is no longer available.
It is a damn good game that should be in any fan's collection. As much as I liked the first game, I preferred the second one. The Alien campaign was cool too, you get to go through the Alien life-cycle.
The sound effects were brilliant, they were pretty much movie accurate. Could be a factor in the licence issue actually.
It is something that should be given an updated re-release, perhaps even to consoles.
Multiplayer was fun because it could include the Alien life-cycle. Makes the aliens a bit harder to play but its immersive and if you survive long enough (or get lots of kills?) you morph into a praetorian.