A recent game development trend is natural user interfaces. This paper presents a motion-tracking platform, which provides natural interfaces for multi-player arcade video games. The platform is composed of acceleration sensors and transmitters/receivers of radio frequency and ultrasonic signals. The game players operate physical devices in the real world, and the positions and orientations of the devices are computed and represented in the virtual devices of the game world. The prototype proves that various off-the-shelf wireless sensor nodes can be integrated, resulting in a new type of natural interface for arcade video games.