Its been a while since I've played this game, and honestly... It was extremely short, yet with three different campaigns I thought it was a different view of the game and actually quite fun. If your a hard-core gamer, its probally a pass.
But, The whole pick on a kind of (Age of Empires) theme, it wouldn't even compare. You can still have fun with it though, and watch Aliens swarm down on your human troopers just for the heck of it and watch hand crawlers latch onto your soldiers.
The camera failed in its point, where as you could only see if you moved your men, but even then its always in one view.
The action and combat was slightly obscure and a little difficult.
But, personally to me as a Predator fan... The story more then made up for it. It gave me about five-ten hours of play. And I still had fun, worth to rent, yet no need to buy.