To start with more chances (to save Marian or live, your choice) hold SELECT on the Options Screen and enter L, R, DOWN, L, R, DOWN, L, R, RIGHT.

While playing go up to any enemy and punch him /her three times. On the third punch the enemy will crouch, dont hit them when they are crouching or they will die. Instead wait untill they stop crouching and punch them another three times. If you keep repeating this on an enemy you will get heaps of points, every 20000 points you get a spare life.

For a tougher time hold SELECT on the Options Screen and enter UP, UP, DOWN, DOWN, LEFT, RIGHT, LEFT, RIGHT.

On the options menu, hold SELECT and press R, L, R, and L.