Killzone is probably one of the best ps2 games out there it has a great story line the graphics are good and the great variety of weapons you get to choose from and the characters you get to choose from all have thier advantages and disadvantages and its a long game to keep you occupied and the maps you play on are so cool. If you havent played it yet you should at least rent it. And it is a 1st person shooter about the ISA getting attacked by the evil Helghast and one of the ISA generals is ......... HA HA HA im not going to ruin it for you. But anyways you need to get up to your space station floating around the world your on but you need to get through tons of Helghast to get a shuttle to get to the space station controlled by the ISA. Its a great way to take stress off your mind by shooting helghast in the brain like 7 times then shooting thier torso 200 times with a chain gun or just hit them with a huge a$$ missle from a rocket launcher.
O these are Helghast.