SPLATTERHOUSE

No brainer... no brainer, during the first level you will go through several "tutorial" sequences where it tells you haw to perform a move...
Midway through the first level, you will beat a guy until he flashes red, and the game will tell you to press "b" for splatterkill... it will then prompt you with directions for the right, and left sticks... you will either rip the mouth open, or crush the enemy's skull inititally...
Just a note, watch the mini "cut scenes" before your splatterkills to learn what right and left stick moves to do with the particular cut scene...you dont get much time to do the move and can be frustrating at first