In this paper, we present a real-time prototype of a robot boxing game based on a novel interaction method which provides a simpler control for a miniature humanoid. Specifically, an upper body of the robot mimics a user's upper body motion, while a lower body of the robot moves autonomously towards a target object (an opponent robot). To the best of our knowledge this is the first robot boxing game which provides semi-autonomous control based on natural human motions. Questionnaire interview shows the users feel immersive gaming experience and companionship with the robot in the living room.