One of the oddest games you could ever get your hands on...
Gameplay - This was very different, yet great. This isn't like your typical FPS where you can pretty much explore any coridor, it's a little more restraining. You won't be using your analog stick to move your character, other then when you're deciding what path to take at a crossing. Rather, you'll be pressing the A button (I don't know what that transfers into for the PS2 version). This is so because the game is basically on rails. It may feel a little werid at first, but it adds to the odd feeling of the game. You'll have many different characters to chose from in the game, each with their own weapon, specials, and quirky feel. Most of the game you'll be shooting the crap out of heaven smiles, and going through many puzzles throughout. Value - The main game takes about 20 hours. There is also a Hard mode, Killer8, and Hopper7, which are pretty much optional, but still interesting.
Story - This must be mentioned. The story to Killer7 alone is worth it. This story will have you confused, mad, make you become liberal (experiences may vary), and almost crying at some points. It deals with political issues within the US and Japanese governments. In conclusion, Killer 7 is almost a must have game. In reality, I know not everyone will like it, mostly because of the gameplay. If you don't mind something that's a little out there, I defenitely think you should give it a try.