Erm, so there’s only three “chapters”? Oh well.
The last one started off in some sort of snowy wasteland, then moved underground to the Lost City of Atlantis, then moved through some caves, some strange gravity-warping temples, and finally into an alien spaceship.
I can see, actually, that Prey nicked a few ideas from this game too, with the wall-walking and stuff.
The last few levels were pretty difficult, as health pickups became fewer and baddies increased in number (and size!) quite dramatically. Eventually, I reached the boss at the end of the game. I won’t spoil it, but he was very easy due to the piles of regenerating ammo, health and armour. He did take aaaaaaages to kill though – easily half an hour. Good job I didn’t die!
So, Game Over – WIN!