Originally released by SEGA in Japan in 2001 for the Dreamcast and PlayStation2 computer entertainment system, followed by a North American release only for the PlayStation 2 and European release on both platforms in early 2002, Rez was developed by SEGA's United Game Artists ("UGA") division. Tetsuya Mizuguchi, former president of UGA and current chief creative officer of Q Entertainment, conceptualized and produced the fast-action shooter, which is known to be one of the most unique, offbeat and eccentric games ever released.

Carrying the slogan "Rez will open your senses…let's go to synaesthesia," the dynamic, total integration of visual presentation, sound and player's input provided a rich aesthetic experience that was difficult to describe in words. While the basic gameplay was simple, critics called Rez "the ultimate audiovisual experience" and emphasized that "it must be seen and heard to be fully understood." The old-school vector style graphics, sensory response and beat synchronization presented by the game set aside the title apart from the rest of the games that were released during that time.

Rez consisted of five different levels, each with its own unique visual theme and style, musical track and a boss battle at the end. The game also featured several different modes and plenty of unlockable elements, giving it a higher replay value. To further enhance the Rez experience, artists including Coldcut, Adam Freeland, Joujouka, Ken Ishii and Keiichi Sugiyama (SEGA's Wave Master) contributed tracks to the game.

Rez HD (title pending) for the Xbox LIVE Arcade will be a direct port of the original, delivered in hi-definition and 5.1 surround sound. Further details on Rez HD for the Xbox LIVE Arcade including pricing will be revealed at a later date.

Rez HD is being developed for the Xbox LIVE Arcade with a target release date of Q1 2008.