in Japan on 31 May 1991 and later in Europe by Sega on July 1991. The game was later converted to the PC Engine CD-ROM² add-on and was published exclusively in Japan by Naxat Soft on 18 September 1992. The Japanese release is able to play fine on American Sega Genesis consoles. Like most early titles it had no region protection, nor had the European release been PAL-optimized. To expand the plot, the Mega Drive version added an introductory sequence to the game. This introduction does not appear in the arcade original nor in the PC Engine CD-ROM² versions; rather, a different intro takes place with a blue-windowed ZIG. The PC Engine CD-ROM² added two new levels — 5th (Deeva) and 10th (Vacura). The Mega Drive port was later released in North America by independent publisher Retro-Bit in 2020. Zero Wing was planned to be included as part of the Toaplan Arcade 1 compilation for Evercade. It was released on December 15, 2022. On June 30, 2022, Zero Wing was re-released on the Nintendo Switch Online + Expansion Pack. On August 18, 2022, Bitwave Games and Toaplan jointly announced that Zero Wing would be releasing onto Steam as a standalone title in 2022, and will also be available in a game bundle along with Twin Cobra, Truxton, and Out Zone. The Steam release will include a "range of quality-of-life enhancements, such as stunning pixel-perfect graphics, rewind, achievements, online leaderboards, sidebar indicators, and a brand new Very Easy mode". Following a delay, it was released on Steam and GOG.com on February 14, 2023. Reception In Japan, Game Machine listed Zero Wing on their 15 November 1989 issue as being the fourth most-successful table arcade unit of the month, outperforming titles such as Jitsuryoku!! Pro Yakyū and U.N. Squadron. The game received a positive critical reception upon release. Computer and Video Games scored it 93%, including ratings of 92% for graphics, 93% for sound, 90% for playability, and 89% for lastability. They praised "the great intro sequence", "super-smooth gameplay, beautifully defined graphics, rocking sound track, amazing explosions and incredible end-of-level bosses", concluding that it is "the game which breaths (sic) new life into shoot 'em ups on the Megadrive". Mean Machines scored it 91%, including ratings of 92% for presentation and graphics, 88% for sound, 90% for playability, and 89% for lastability. They praised the "ace" opening sequence, "detailed" graphics, "real good"