Psyvariar: Medium Unit is a sci-fi vertical-scrolling shoot-'em-up developed by Success and released by Taito for arcades (using PS1-based Taito G-NET hardware) exclusively in Japan on March 2000.
The game later received an enhanced re-release on September 2000 as Psyvariar: Revision. Along with updated graphics and rearranged stages, this version revamps the buzz system (now allowing players to buzz the same bullet multiple times), adds a new "replay mode" (where players can choose a stage and watch its high score replay before starting).
Both the original and Revision versions were later ported by SKonec to the PlayStation 2 and released as Psyvariar: Complete Edition in both Japan (by Success on March 28, 2002) and Europe (by Xplosiv on September 29, 2003). The Japanese version received two special editions: one with an audio CD of the game's soundtrack (Special Sound Box) and one with a video DVD of both versions being completed by experts (Special Capture Box). This compilation was later digitally re-released for the PlayStation 3 (as a Game Archives title) on April 17, 2013.
Both PS2 versions in the compilation were also released separately by Success a year later as part of their SuperLite 2000: Shooting series of budget games (with the port of the original released on September 11, 2003 and the port of Revision released on October 9, 2003).
Both versions of the game later received HD remakes as part of CITY CONNECTION's 2018 series revival Psyvariar Delta.