Touhou. Like this:
http://www.youtube.com/watch?v=z4zLwlpPobU
The defacto most popular game series in Japan. It's also known as the hardest of its genre.
This particular game out of the series, Shoot the Bullet, is a bit different. It's an extra game, but that doesn't make it any less hard.
http://www.youtube.com/watch?v=BQLIaZUOnBU
More average for the series, difficulty is still ridiculous.
Apparently the only reason there's no official English version is because the game is too hard for Americans.
I will give you props if you really manage to recreate the game. You will run in the hundreds of thousands (Probably cutting a few million) of spheres if you try to do it normally, so try to include cloning that occurs during play.