Also known as: 稀翁玉, きおうぎょく
Kioh Gyoku (稀翁玉, lit. "Rare Venerable Orb") is a vertical-scrolling danmaku shoot 'em up, and is the second official game in the Seihou Project by "Shunsatsu sare do?" (at time part of Amusement Makers). It was released specifically for the Windows operating system around December time in 2001. It is a unique game where two players indirectly battle one another by charging and releasing charge attacks and bombs upon the other player, similar in the style of Phantasmagoria Of Dim.Dream.
https://en.touhouwiki.net/wiki/Kioh_Gyoku