The sooner you shoot the note, the more points you get. There are all in all fourty levels and you can get tens of thousands of points if you're quick enough. In the end there is a high score table displayed and you can enter your name if you get into the top ten list.
If you miss note there are some penalty points, subtracted form your current score, so watch the coming notes carefully. If there is not sufficient number of points gained within one level, the task must be taken again, until there is enough points to proceed to the next.

Please download the program using the following link:
http://www.muzzician.com/dl/nhsetup.exe