Earn the following ranks by performing the corresponding tasks:

"Sushi Chef" rank
In any level, use the knife to kill lots of people. Note: This was accomplished on the You Better Watch Out... level with 88 people killed with a knife.

"Pianoman" rank
Kill the majority of your victims using Fiberwire. You will be dubbed "Pianoman." Note: This was accomplished on A New Life level with 15 dead.

Second life hint:
Just before dying and your screen becomes red, kill severalenemies before dying the screen will return to normal and you will continue living. However, one bullet will be enough to kill you.