Been playing the original Double Dragon for years now, and had to fire up my em' right after hearing this. I absolutely love the take you did on this, and the loop sounds really well.
If I have any complaint whatsoever, its that for a loop it kinda drops off for a split second or two, but it's definitely noticeable when it does. Still, if you think about doing the whole game, like maybe a major remix that'd take the listener through a good memory visit, that'd be my request.
Man, I wish I could edit the music in my games and swap them out for decent quality remixes like this. Oh well, I'll just have to settle for pausing the game and switching what song plays. ^_^'