Defeat most bosses
When fighting Bosses use the headbutt or flying kick move Forward Forward B then run back to the other side of the screen Then repeat this process Your character will be able to beat most Bosses easily For the Boss on the rocket play as a Double Dragon then hold Down and press B when near Try to keep him in the air
Defeating the third Boss
Play through the third level with roper and reach the Boss Duck when he lifts up his gun then attack once or if possible twice Watch out for the butt of his gun Keep on repeating this until he is defeated
Extra lives
Start a two player game and play all the way to the end of level 11 Do not enter level 12 yet Instead turn on player two and use up all of his lives Continue the game as player two then repeat this process until all of player twos continues are used Then continue the game as player one However if all the pods on Level 11 were broken you will have eight more lives and will have earned more through the points awarded while defeating player two Two more lives can be obtained by going through level 11 again