Also, the recent 1cc Marathon (https://www.twitch.tv/1ccmarathon) hosted by Pasky had this game as one of the featured 1cc's that was to be attempted. FunkDoc was running this game, and unfortunately he wasn't able to get the clear during the marathon.
This game is exceptionally hard to complete in 1 credit, as there are absolutely no health refills for all 11 levels of the game!
It seems that you almost always want you opponent to have a non-throw-able weapon in their hands if possible, such as the wooden stick. The reason being is that the actual attack from those weapons is about twice as slow as your attacks!
Another tactic that is more advanced - almost any move in the game can be cancelled into another move. You'll often see me alternate punch-kick-punch-kick when I get an opening. Or the rear-facing elbow technique - cancelling that with either a kick or a dash makes it even faster to recover.
Played on wolfMAME .177 - no cheats, hacks, or auto fire were used. Played on default settings (medium difficulty). INP verified and available for download at MARP: http://replay.marpirc.net/r/pitfight6