A "Special Package" version of the PlayStation 2 release of the game was sold in Japan only, including a USB device called a Trance Vibrator, which pulses in time with the music. The intended use of the device would be to hold it, put it in a pocket, or sit on it while playing (a pouch was provided to protect the device); similar to the DualShock, it would vibrate in time with the music, but much more powerfully than the DualShock's own feedback, helping to extend the synesthesia to the player's feeling of touch. While not explicitly marketed as a sex toy or masturbatory aid, it has reportedly been used as such.