for new hires while using his work and engine from Hellfire before ultimately deciding with releasing the game to the market, which made it a more practical learning experience for the new developers. However, Uemura felt that both stage design and characters were "cobbled together", leading the game's world being "kind of a mess" and he also stated the project turned into a "battle royale", as staff from both Hellfire and Truxton were mixed with the new recruits. Sound also proved to be very divisive as Uemura, Yuge and Tomizawa wrote several songs for the game with their own individual styles, though Uemura claimed this was due to dividing the work, while Yuge stated he would go to rest and drink after being stuck when composing for the title during work hours. Due to being a training project, Uemura stated the team had freedom to "just fool around" and several features were integrated into the title such as warps, which was taken from Slap Fight. Uemura also revealed that the reason for enemies spawning suicide bullets during loops of higher difficulty was in response to hardware limitations regarding sprites. Both the single-player and co-op versions were also planned from the beginning of development due to pressure to make two-player games at the time. The alien Pipiru was designed by Ogiwara, though Uemura claimed such character was not planned. The Sega Mega Drive version of Zero Wing was created by the same staff from the original arcade release, with Uemura overseeing development in-house. Both Uemura and Tataka have stated that working with the Mega Drive proved to be difficult due to several restrictions imposed by the hardware. According to both Uemura and Yuge, the poor English translation in the Mega Drive version was handled by a then-member of Toaplan in charge of export and overseas business, whose English was "really terrible". The Mega Drive port features arranged music by Noriyuki Iwadare. The PC Engine CD-ROM² version was outsourced by an "acquaintance" from defunct developer Orca, with Uemura handling sound. Release Zero Wing was first released in arcades on July 1, 1989 by Namco in Japan, and then by Williams Electronics for North America in April 1990. In 1989, an album containing music from the title was co-published exclusively in Japan by Scitron and Pony Canyon. Zero Wing was first ported to the Sega Mega Drive by Toaplan and was first published