International Karate was the most popular marital arts game at the time but Melbourne Houses release Way of the Exploding Fist was in my opinion, by far the best release on the Commodore 64.
In the mid 1980's the boundaries of the C64's capability had not been pushed as much as it was during the later part of the decade. So therefore 'Fist's digitized scream and marital arts sounds were absolutely spellbinding at the time.
Fist also had superb intro music - the C64 was way ahead of its rivals in this regard due to the Sid Chip. The game itself was fairly simplistic in front of no more than 6 well drawn static background and you had to win on points to progress to the next.
The single player was challenging by most fun was had in 2 player mode. Unlike most martial arts computer games you could not win this just by hammering the joystick button as fast as you could and it was very tactical at times - for instance you could draw bouts and then the judge would decide who had been more aggressive in the event of a tie. I'm sure those judges were bribed you know?
Fist was very successful and spawned a sequel - Way of the Exploding Fist 2. It was enjoyable but nowhere near as good as it dispensed with the static background and was more of a sideways scroller where if I recall you killed ducks and other wildlife. Nowhere near as fun.
Super fun still, this would be in my personal collection of C64 all time hits.