Here's a video of a player completing the U.S. version of Double Dragon 3 in one credit. The most impressive about this playthrough is that not only does the player completes the game without buying any of the power-ups (naturally, since otherwise this wouldn't be a real 1CC), but he does it without taking any damage during the first three stages. Granted, he does take advantage of a few bugs which causes some of the bosses (namely Li and Ranzou) to be stuck in a pattern, but still he doesn't suffer much damage from the third stage and onward (which is even more impressive when it's obvious that the game's configuration has health recovery after each stage turned off).
There seems to be a few more differences between the Japanese and overseas arcade versions of Double Dragon 3 besides the removal of the character select screen and the addition of the shop system in the latter. Apparently some of the enemy attacks deal more damage in the overseas version such as the fireballs shot by Cleopatra during the final battle.
While I still prefer the first two arcade games, Double Dragon 3 is not as bad as I remember. In some ways, I actually prefer it over Combatribes, Technos' other 1990 belt-scroller offering. Don't get me wrong, the whole shop system is still just a gimmicky ploy to sucker credit feeding zaps to spent more money and the game is much better off without it, but it's nice know it's beatable without actually using it.http://nicoviewer.net/sm13916051