Oh. My. God.
This game is really amazing. The story is incredible, but maybe a little bit hard to understand, the characters are all more crazy than the others. The gameplay is really different from the other games, the character is set on "railroad tracks" an you just press A to move forward, press B to turn around. Hold R to take out your gun and A to shoot, special "charge shots" are made by pressing Y then A. Because the enemies are invisible, you'll have to "scan" the area by pressing L while holding your gun. The graphics are really nice, they are quite weird, but it makes the game very interesting, because since they are very far from realism, they could create insane creatures, boss, and environments.
The sounds and music are creepy........ They are great but they gives you the chills...... Just the demoniac laugh when you press "continue" is really scary. Another huge point that makes Killer7 an outstanding game.
As I said before, the different personas are really special and they each have their unique abilities: invisibility, super speed, resurrection, etc. You level-up the characters by giving them blood that you gain by killing the Heaven Smiles (enemies).
A real masterpiece that everybody should try.