radio_zonde
For a type of balloon, use radiosonde.
A 2002 freeware top-down shoot'em up by RANYON_(Hiranyon) for Windows PC.
Circle Ruminant's Whimper's doujin shoot 'em up Hellsinker. and this game share the same universe.
Characters
* MAHILO (Mahiro)
* YOXOLA (Yozora)
* DENLI (Denri)
* AOXOLA (Aozora)
See also
* Fanmade wiki: http://www40.atwiki.jp/hellsinker/
* Vector software library: http://www.vector.co.jp/soft/win95/game/se313786.html
* [Wikipedia] / [Nicopedia] / [pixiv encyclopedia]