Official UK Playstation 2 Magazine
Yes, progress is rapid, well, until you finally
meet the Greys, that is. These intergalactic
bastards have a nasty habit of spawning endless troopers, and fights you had reasonably under control suddenly become health-sapping wars on two fronts - one to kill the alien, another to deal with the troops. It's a struggle just to keep your health from draining away before you've even fired a shot at the target - the worst fights are much like trying to keep water in a sieve. Checkpoints are generally well placed however, and you're hours in before even seeing the dreaded Greys, which makes things feel pretty climactic. It's supposed to be a challenge.
And the things you see! The furious battles, the gore of past attacks, the secret experiments, the captured craft, the hoaxes in progress, the conspiracies, the boss battles, the caverns of machinery, the sharks with guns (really), the atmospheric mystery of the Greys... level, character and story design is all incredibly strong.