The initial ideas for "Bangai-O" came from Treasure programmer Mitsuru Yaida who wanted to challenge himself by programming an extreme number of bullets on the screen at once. Journalists agree that Yaida was most likely inspired by the 1984 Japanese computer game "Hover Attack". The team developed the game with a focus on creating enjoyable gameplay, and opted for simple graphical effects to preserve the game's speed. "Bangai-O" was released on the Nintendo 64 and was limited to a run of 10,000 copies because of publisher Entertainment Software Publishing's belief it had niche appeal. The team replaced most of the graphics and audio, changed some gameplay elements, and re-released it on the Dreamcast three months later, a version later released internationally.