A classic Apple II game by Broderbund.
You play a guy whose job it is to go rescue his princess who has been captured by an evil overlord. There are three levels of goons to get through and all you have are you karate skills.
You had two stances: one for fighting and one for running. Your only weapons were your high, middle and low punches and high, middle and low kicks.
One thing you have to know is that after you kill the final goon and get to the princess, you have to run into her arms instead of walking in that fighting stance towards her or else she'll kill you.
game hints: http://www.gamefaqs.com/computer/apple2/file/karateka.txt