To beat Neo. Cortex at the end of the game, you must wait until he throws his exploding mines. After they explode, immediatley attack Cortex and knock him into the sewer. Do this three times to beat him. Watch out, however, for your friend Aku Aku and Cortex's boss Uka Uka are battling in the room with you. If you touch them or the lasers they shoot each other, you will die. Be careful, each time you hit Cortex, it becomes tougher to dodge Aku Aku and Uka Uka.