On PC or Xbox you can modify the game to see the original kill scenes. They had to be edited because the ESRB gave the game an AO rating.
Overall the game is a good time. Without the mod it's less violent but it's still a good 3rd person shooter for it's time. In fact I remember it being one of my favorite games for quite a while. It's not often we see a comic book character done right in a game but the developers nail it with this one. If you can get your hands on it I highly suggest you give it a shot.