Just one of the more insane series "bullet hell" shooters I've played.
Created by a lone Japanese dude in his spare time who does the all the music/artwork/programming by himself and blogs a lot about beer.
Extra Stage of Touhou 6
http://www.youtube.com/watch?v=Vnmvm4RyOlYGameplay video of Touhou 11 (which just came out this summer)
http://www.youtube.com/watch?v=FtEbJ-s-i-UThe saving grace about the genre that keeps you from going completely insane is that your hitbox is insanely small (smaller than your character model and usually only a few pixels wide).
Link to download:
http://www.doujinstyle.com/touhougames.phpEnglish Patches can be found linked from the wiki here:
http://touhou.wikia.com/wiki/Touhou_Wiki