Learn Moves Quickly
When you start Mission one, punch all the enemies you see. You earn hearts faster, for example, you 
usually learn to jump-kick at Missions two or three. You may earn the jump-kick by the end of Mission 
one if you punch people non-stop.

Level one glitch
Start playing the first level of Double Dragon until you see the second set of double doors. When you get 
there, take notice of the two vertical bars on the right hand wall. Kill all of the enemies, and then center Billy 
between the bars. From there, you can climb up and down without turning the characters back to you. If you 
go up, you can go off screen without losing a life. If you are up high, press left or right and you will "teleport" 
to ground level. Note: If you go too far down you will lose a life. 

Quick Ability Gain, Method 2
You can earn all of your hearts on the very first level! you will start off facing two Will's. When you punch a Will, 
you will notice that he crouches down somewhat when you are hitting him. When he crouches down, that signals 
that the next punch will knock him down. So, punch a Will until he crouches down, then let him stay up then go to 
the other Will and do the same thing. Keep taking turns punching them. Dont hit them so much at once or else they 
will fall down and die. Keep punching them until you have the desired amount of hearts the go ahead and finish them off. 

Quick Ability Gains
On Mission 2 you can max out your statistics by climbing the fence, kill the Will at the top then drop down to the 
other side. Move forward and wait for Will to come close. When he reaches the end of the pipes in the background, 
climb back up the fence. Then move your character left until you walk to the edge of the yellow marker. Don't go 
too far left or the badguys will die and the trick won't work. (you'll now they died when the pointer tells you to go 
forward.) Then move back and Will should be invisible. He won't be able to attack, but you can attack him many 
times. If you have the bat, just hit the spot he was standing in over and over until you heart level is seven. You can 
keep hitting as many times as you want provided the time doesn't run out.