It's so good, so original, so interesting it's almost scary.
That's another thing I forgot to mention. You play as a killer with 7 different personalities called Harman Smith - old man on a wheelchair. He dispenses clever lines throughout the game. He is in fact the 7th personality because Garcian Smith is really independent.
Dan Smith - Decent fire power. A little bit slow on reloads. His ability allows him to shoot fire balls by using up vials of serum of thick blood. Has an annoying side effect of blowing of limbs. For example if the weak spot is on the arm and you miss it but hit somewhere else on arms the arm will fly off and the weak spot will be gone leaving you to only fire away until the enemy is dead.
Coyote Smith - below avarage fire power. Decent reload speed. His ability allows him to fire more powerful rounds out of his pistol. Also can use serum to leap great heights.
Con Smith - low fire power. Incredibly fast firing speed and reload. His special power is well... I forgot really but he is the fastest of all Smiths. Also has incredible hearing. Lowest vitality of all Smiths.
Kevin Smith - decent fire power. Slow firing but doesn't require reloads. He uses weird bladed boomerangs. Ability allows him to become invisible and to walk trough walls.
Mask de Smith - Incredibly big fire power. Able to kill most of enemies with 1-2 shots. Must reload after every shot, doesn't get blood for kills, highest vitality of all Smiths.
Kaede Smith - below decent firepower, slow reload. Able to zoom in for more accurate aiming. Able to consume blood from surroundings to increase the amount of thick blood.
Garcian Smith - weakest firepower of all Smiths. Although has a low recoil, great accuracy and fast reload. Ability to see "smile" further than other Smiths. He can revive dead Smiths. Game is over when he dies.
Would you look at all that variety. Every one will find a favourite Smith. My favorite is Dan. Everytime a Smith dies you return to nearest Harman's Room - safehouse and save-point. You will then have choice to either continue with the Smith dead or switch to Garcian and retrieve the body. It's hard to lose the game on default difficulty setting although it gets tedious to keep reviving those Smiths. It's a real pain to get to that body with Garcian who is the weakest of Smiths. One of the peculiar things is that some levels are harder than bosses. Bosses are mostly easy but fun to fight nevertheless. Killer7 has a lot of interesting character. They are hard to describe but they are the very definition of original. My favourite is the severed head. Music is aye. Not very much to say about it. Puzzles are usually easy but clever.
Killer 7 is unlike anything you've ever seen. Some people might not like it but if you're looking for new expiriences then this is a MUST buy. Simply one of the best games you'll find for PS2.